Item 2. Properties.

At December 31, 2018, we owned or had interests in 197 commercial real estate properties, aggregating approximately 51.6 million net rentable square feet of primarily Class A office properties, including 11 properties under construction/redevelopment totaling approximately 5.3 million net rentable square feet. Our properties consisted of (1) 178 office properties (including nine properties under construction/redevelopment), (2) twelve retail properties, (3) six residential properties (including two under construction) and (4) one hotel. The table set forth below shows information relating to the properties we owned, or in which we had an ownership interest, at December 31, 2018, and it includes properties held by both consolidated and unconsolidated joint ventures.

Properties		Location		% Leased as of December 31, 2018 (1)					Number of Buildings			Net Rentable Square Feet
Office
767 Fifth Avenue (the General Motors Building) (60% ownership)		New York, NY		90.2	%				1			1,853,995
200 Clarendon Street		Boston, MA		98.2	%				1			1,763,530
399 Park Avenue		New York, NY		73.3	%				1			1,573,999
601 Lexington Avenue (55% ownership) (2)		New York, NY		99.3	%				1			1,435,543
Salesforce Tower (95% ownership)		San Francisco, CA		69.9	%				1			1,420,682
Times Square Tower (55% ownership)		New York, NY		98.8	%				1			1,247,805
100 Federal Street (55% ownership)		Boston, MA		98.2	%				1			1,238,184
800 Boylston Street - The Prudential Center		Boston, MA		97.8	%				1			1,235,538
Colorado Center (50% ownership) (3)		Santa Monica, CA		99.3	%				6			1,117,647
Santa Monica Business Park (55% ownership) (3)		Santa Monica, CA		94.5	%				14			1,103,882
599 Lexington Avenue		New York, NY		98.9	%				1			1,062,481
Bay Colony Corporate Center		Waltham, MA		93.4	%				4			1,000,449
250 West 55th Street		New York, NY		97.2	%				1			967,323
Embarcadero Center Four		San Francisco, CA		87.6	%				1			939,760
111 Huntington Avenue - The Prudential Center		Boston, MA		100.0	%				1			860,455
Embarcadero Center One		San Francisco, CA		83.5	%				1			830,248
Atlantic Wharf Office (55% ownership)		Boston, MA		100.0	%				1			793,827
Embarcadero Center Two		San Francisco, CA		98.3	%				1			791,294
Embarcadero Center Three		San Francisco, CA		96.8	%				1			781,900
Capital Gallery		Washington, DC		100.0	%				1			631,029
South of Market		Reston, VA		80.5	%				3			623,666
Metropolitan Square (20% ownership) (3)		Washington, DC		83.6	%				1			613,425
Mountain View Research Park		Mountain View, CA		95.5	%				15			542,289
901 New York Avenue (25% ownership) (3)		Washington, DC		90.9	%				1			539,435
Reservoir Place		Waltham, MA		92.7	%				1			526,985
680 Folsom Street		San Francisco, CA		100.0	%				2			524,793
101 Huntington Avenue - The Prudential Center		Boston, MA		94.3	%				1			506,476
601 and 651 Gateway		South San Francisco, CA		94.5	%				2			506,279
Fountain Square		Reston, VA		90.6	%				2			497,259
601 Massachusetts Avenue		Washington, DC		98.4	%				1			478,818

Properties		Location		% Leased as of December 31, 2018 (1)					Number of Buildings			Net Rentable Square Feet
2200 Pennsylvania Avenue		Washington, DC		100.0	%				1			458,831
One Freedom Square		Reston, VA		96.8	%				1			432,585
Two Freedom Square		Reston, VA		98.7	%				1			421,757
Market Square North (50% ownership) (3)		Washington, DC		82.5	%				1			415,499
One Tower Center		East Brunswick, NJ		36.1	%				1			412,060
140 Kendrick Street		Needham, MA		100.0	%				3			380,987
One and Two Discovery Square		Reston, VA		96.9	%				2			366,990
888 Boylston Street - The Prudential Center		Boston, MA		95.1	%				1			363,320
Weston Corporate Center		Weston, MA		100.0	%				1			356,995
510 Madison Avenue		New York, NY		98.1	%				1			355,592
One Reston Overlook		Reston, VA		100.0	%				1			319,519
535 Mission Street		San Francisco, CA		100.0	%				1			307,235
Waltham Weston Corporate Center		Waltham, MA		89.8	%				1			301,667
Wisconsin Place Office		Chevy Chase, MD		99.0	%				1			299,186
230 CityPoint		Waltham, MA		93.5	%				1			296,306
540 Madison Avenue (60% ownership) (3)		New York, NY		82.3	%				1			283,727
355 Main Street		Cambridge, MA		100.0	%				1			265,342
Reston Corporate Center		Reston, VA		100.0	%				2			261,046
611 Gateway		South San Francisco, CA		50.4	%				1			260,197
Democracy Tower		Reston, VA		100.0	%				1			259,441
New Dominion Technology Park - Building Two		Herndon, VA		100.0	%				1			257,400
200 West Street		Waltham, MA		79.7	%				1			256,245
1330 Connecticut Avenue		Washington, DC		87.2	%				1			251,874
10 CityPoint		Waltham, MA		98.1	%				1			241,199
New Dominion Technology Park - Building One		Herndon, VA		100.0	%				1			235,201
510 Carnegie Center		Princeton, NJ		100.0	%				1			234,160
500 North Capitol Street, N.W. (30% ownership) (3)		Washington, DC		100.0	%				1			230,860
90 Broadway		Cambridge, MA		96.6	%				1			223,771
3625-3635 Peterson Way (4)		Santa Clara, CA		100.0	%				1			218,366
255 Main Street		Cambridge, MA		92.4	%				1			216,023
77 CityPoint		Waltham, MA		100.0	%				1			209,707
Sumner Square		Washington, DC		97.6	%				1			208,892
University Place		Cambridge, MA		100.0	%				1			195,282
300 Binney Street		Cambridge, MA		100.0	%				1			195,191
North First Business Park (4)		San Jose, CA		90.6	%				5			190,636
2600 Tower Oaks Boulevard (5)		Rockville, MD		52.6	%				1			179,421
150 Broadway		Cambridge, MA		100.0	%				1			177,226
191 Spring Street		Lexington, MA		100.0	%				1			170,997
Lexington Office Park		Lexington, MA		77.3	%				2			166,775
206 Carnegie Center		Princeton, NJ		100.0	%				1			161,763
210 Carnegie Center		Princeton, NJ		100.0	%				1			159,468
Kingstowne Two		Alexandria, VA		63.4	%				1			156,089
105 Broadway		Cambridge, MA		100.0	%				1			152,664

Properties		Location		% Leased as of December 31, 2018 (1)					Number of Buildings			Net Rentable Square Feet
212 Carnegie Center		Princeton, NJ		65.5	%				1			151,547
Kingstowne One		Alexandria, VA		86.4	%				1			151,483
214 Carnegie Center		Princeton, NJ		49.1	%				1			148,942
2440 West El Camino Real		Mountain View, CA		100.0	%				1			141,392
506 Carnegie Center		Princeton, NJ		32.3	%				1			140,312
Two Reston Overlook		Reston, VA		100.0	%				1			134,615
508 Carnegie Center		Princeton, NJ		100.0	%				1			134,433
202 Carnegie Center		Princeton, NJ		85.2	%				1			134,381
804 Carnegie Center		Princeton, NJ		100.0	%				1			130,000
Annapolis Junction Building Seven (50% ownership) (3)		Annapolis, MD		100.0	%				1			127,229
Annapolis Junction Building Eight (50% ownership) (3)		Annapolis, MD		—%					1			125,685
504 Carnegie Center		Princeton, NJ		100.0	%				1			121,990
101 Carnegie Center		Princeton, NJ		100.0	%				1			121,620
502 Carnegie Center		Princeton, NJ		94.8	%				1			121,460
701 Carnegie Center		Princeton, NJ		100.0	%				1			120,000
Annapolis Junction Building Six (50% ownership) (3)		Annapolis, MD		75.2	%				1			119,339
325 Main Street		Cambridge, MA		100.0	%				1			115,361
1265 Main Street (50% ownership) (3)		Waltham, MA		100.0	%				1			114,969
7601 Boston Boulevard		Springfield, VA		100.0	%				1			114,028
201 Spring Street		Lexington, MA		100.0	%				1			106,300
7435 Boston Boulevard		Springfield, VA		83.4	%				1			103,557
104 Carnegie Center		Princeton, NJ		27.0	%				1			102,830
103 Carnegie Center		Princeton, NJ		69.9	%				1			96,332
8000 Grainger Court		Springfield, VA		—%					1			88,775
33 Hayden Avenue		Lexington, MA		100.0	%				1			80,872
7500 Boston Boulevard		Springfield, VA		100.0	%				1			79,971
7501 Boston Boulevard		Springfield VA		100.0	%				1			75,756
Reservoir Place North		Waltham, MA		—%					1			73,258
105 Carnegie Center		Princeton, NJ		56.3	%				1			69,955
32 Hartwell Avenue		Lexington, MA		100.0	%				1			69,154
250 Binney Street		Cambridge, MA		100.0	%				1			67,362
302 Carnegie Center		Princeton, NJ		96.1	%				1			64,926
164 Lexington Road		Billerica, MA		—%					1			64,140
195 West Street		Waltham, MA		100.0	%				1			63,500
7450 Boston Boulevard		Springfield, VA		100.0	%				1			62,402
7374 Boston Boulevard		Springfield, VA		100.0	%				1			57,321
100 Hayden Avenue		Lexington, MA		100.0	%				1			55,924
181 Spring Street		Lexington, MA		100.0	%				1			55,793
8000 Corporate Court		Springfield, VA		100.0	%				1			52,539
211 Carnegie Center		Princeton, NJ		100.0	%				1			47,025
7451 Boston Boulevard		Springfield, VA		67.4	%				1			45,615
7300 Boston Boulevard		Springfield, VA		100.0	%				1			32,000
92 Hayden Avenue		Lexington, MA		100.0	%				1			31,100
17 Hartwell Avenue		Lexington, MA		100.0	%				1			30,000
453 Ravendale Drive		Mountain View, CA		100.0	%				1			29,620

Properties		Location		% Leased as of December 31, 2018 (1)					Number of Buildings			Net Rentable Square Feet
7375 Boston Boulevard		Springfield, VA		100.0	%				1			26,865
690 Folsom Street		San Francisco, CA		100.0	%				1			26,080
201 Carnegie Center		Princeton, NJ		100.0	%				—			6,500
Subtotal for Office Properties				91.3	%				169			43,750,746
Retail
Prudential Center (retail shops)		Boston, MA		96.1	%				1			595,334
Fountain Square Retail		Reston, VA		98.0	%				1			223,030
Kingstowne Retail		Alexandria, VA		100.0	%				1			88,288
Santa Monica Business Park Retail (55% ownership) (3)		Santa Monica, CA		92.3	%				7			74,242
Star Market at the Prudential Center		Boston, MA		100.0	%				1			57,235
The Point		Waltham, MA		84.7	%				1			16,300
Subtotal for Retail Properties				96.6	%				12			1,054,429
Residential Properties
Signature at Reston (508 units)		Reston, VA		48.8	%		(6)		1			517,783			(7)
The Avant at Reston Town Center (359 units)		Reston, VA		89.4	%		(8)		1			355,374			(9)
Proto Kendall Square (280 units)		Cambridge, MA		56.4	%		(10)		1			166,717			(11)
The Lofts at Atlantic Wharf (86 units)		Boston, MA		95.3	%		(8)		1			87,097			(12)
Subtotal for Residential Properties				65.6	%				4			1,126,971
Hotel Property
Boston Marriott Cambridge (437 rooms)		Cambridge, MA		84.6	%		(13)		1			334,260			(14)
Subtotal for Hotel Property				84.6	%				1			334,260
Subtotal for In-Service Properties				91.4	%				186			46,266,406
Properties Under Construction/Redevelopment (15)
Office and Retail
The Hub on Causeway - Podium (50% ownership) (3)		Boston, MA		88.0	%				1			385,000
145 Broadway		Cambridge, MA		98.0	%				1			485,000
Dock 72 (50% ownership) (3)		Brooklyn, NY		33.0	%				1			670,000
17Fifty Presidents Street		Reston, VA		100.0	%				1			276,000
20 CityPoint		Waltham, MA		63.0	%				1			211,000
100 Causeway Street (50% ownership) (3)		Boston, MA		70.0	%				1			627,000
7750 Wisconsin Avenue (Marriott International Headquarters) (50% ownership) (3)		Bethesda, MD		100.0	%				1			740,000
Reston Gateway		Reston, VA		80.0	%				2			1,062,000
Redevelopment
One Five Nine East 53rd Street (55% ownership) (16)		New York, NY		90.0	%				—			220,000
Residential
The Hub on Causeway - Residential (440 units) (50% ownership) (3)		Boston, MA		N/A					1			320,000
MacArthur Station Residences (402 units) (17)		Oakland, CA		N/A					1			324,000

Properties		Location		% Leased as of December 31, 2018 (1)					Number of Buildings			Net Rentable Square Feet
Subtotal for Properties Under Construction/Redevelopment				78	%		(18)		11			5,320,000
Total Portfolio									197			51,586,406

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(1)	Represents signed leases for in-service properties which revenue recognition has commenced in accordance with generally accepted accounting principles in the United States (“GAAP”).

(2)	Excludes the portion that was removed from the in-service portfolio during the third quarter of 2016 as part of a planned redevelopment.

(3)	Property is an unconsolidated joint venture.

(4)	Property is held for redevelopment.

(5)	On January 24, 2019, we completed the sale of this property (See Note 19 to the Consolidated Financial Statements).

(6)	This project was completed and fully placed in-service on June 7, 2018 and is still in its initial lease-up period. Percentage leased is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(7)	Includes 24,542 square feet of retail space which is 100% leased as of December 31, 2018. Note that these amounts are not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(8)	Note that these amounts are not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(9)	Includes 26,179 square feet of retail space which is 100% leased as of December 31, 2018. Note that this amount is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(10)	This project was completed and fully placed in-service on September 1, 2018 and is still in its initial lease-up period. Percentage leased is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(11)	Includes 14,527 square feet of retail space which is 100% leased as of December 31, 2018. Note that this amount is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(12)	Includes 9,617 square feet of retail space which is 100% leased as of December 31, 2018. Note that this amount is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(13)	Represents the weighted-average room occupancy for the year ended December 31, 2018. Note that this amount is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(14)	Includes 4,260 square feet of retail space which is 100% leased as of December 31, 2018. Note that this amount is not included in the calculation of the Total Portfolio occupancy rate for In-Service Properties as of December 31, 2018.

(15)	Represents percentage leased as of February 22, 2019, including leases with future commencement dates.

(16)	The low-rise portion of 601 Lexington Avenue.

(17)	This project is subject to a 99-year ground lease (including extension options) with an option to purchase in the future.

(18)	Excludes residential units.

Percentage Leased and Average Annualized Revenue per Square Foot for In-Service Properties

The following table sets forth our percentage leased and average annualized revenue per square foot on a historical basis for our In-Service Properties.

		December 31,
		2018				2017				2016				2015				2014
Percentage leased (1)		91.4		%		90.7		%		90.2		%		91.4		%		91.7		%
Average annualized revenue per square foot (2)			$66.63				$63.66				$62.54				$60.89				$58.97

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(1)	Represents signed leases, excluding hotel and residential properties, for which revenue recognition has commenced in accordance with GAAP.

(2)

Represents the monthly contractual base rents and recoveries from tenants under existing leases as of December 31, 2018, 2017, 2016, 2015 and 2014 multiplied by twelve. These annualized amounts are before rent abatements and include expense reimbursements, which may be estimates as of such date. The aggregate amounts of rent abatements per square foot under existing leases as of December 31, 2018, 2017, 2016, 2015 and 2014 for the succeeding twelve-month period were $0.97, $1.67, $1.18, $0.60, and $1.05, respectively.

Top 20 Tenants by Square Feet

Our 20 largest tenants by square feet as of December 31, 2018 were as follows:

		Tenant		Square Feet					% of In-Service Portfolio
1.		U.S. Government		1,389,348			(1)		3.23	%
2.		Arnold & Porter Kaye Scholer		877,484					2.04	%
3.		Kirkland & Ellis		861,214			(2)		2.00	%
4.		Biogen		772,212					1.79	%
5.		Wellington Management		648,032			(3)		1.51	%
6.		Bank of America		608,420			(4)		1.41	%
7.		salesforce.com		580,741			(5)		1.35	%
8.		Google		550,524					1.28	%
9.		Ropes & Gray		539,467					1.25	%
10.		Shearman & Sterling		472,144			(6)		1.10	%
11.		O’Melveny & Myers		458,399			(7)		1.07	%
12.		WeWork		448,294			(8)		1.04	%
13.		Weil Gotshal & Manges		413,395			(9)		0.96	%
14.		Genentech		392,540					0.91	%
15.		Ann Inc. (fka Ann Taylor Corp.)		368,463			(10)		0.86	%
16.		Bechtel Corporation		365,606					0.85	%
17.		Snap		358,077			(11)		0.83	%
18.		Mass Financial Services		336,981					0.78	%
19.		Blue Cross Blue Shield		324,050					0.75	%
20.		Finnegan Henderson Farabow		321,798			(12)		0.75	%

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(1)	Includes 157,029 and 1,980 square feet of space in properties in which we have a 50% and 20% interest, respectively.

(2)	Includes 576,798 and 223,424 square feet of space in properties in which we have a 55% and 20% interest, respectively.

(3)	Includes 637,993 square feet of space in properties in which we have a 55% interest.

(4)	Includes 50,887 and 540,559 square feet of space in properties in which we have a 60% and 55% interest, respectively.

(5)	Includes 580,741 square feet of space in a property in which we have a 95% interest.

(6)	Includes 43,661 square feet of space in a property in which we have a 50% interest.

(7)	Includes 304,619 square feet of space in a property in which we have a 55% interest.

(8)	Includes 76,401 and 161,879 square feet of space in properties in which we have a 95% and 20% interest, respectively.

(9)	Includes 385,248 and 28,147 square feet of space in properties in which we have a 60% and 55% interest, respectively.

(10)	Includes 351,865 square feet of space in a property in which we have a 55% interest.

(11)	Includes 358,077 square feet of space in a property in which we have a 55% interest.

(12)	Includes 251,941 square feet of space in a property in which we have a 25% interest.

Tenant Diversification

Our tenant diversification by square feet as of December 31, 2018 were as follows:

Sector	% of In-Service Portfolio
Media & Technology	29%
Legal Services	19%
Financial Services - all other	14%
Other	13%
Other Professional Services	8%
Financial Services - commercial and investment banking	6%
Retail	6%
Government / Public Administration	5%

Lease Expirations (1)(2)

Year of Lease Expiration		Rentable Square Feet Subject to Expiring Leases			Current Annualized Contractual Rent Under Expiring Leases Without Future Step-Ups (3)				Current Annualized Contractual Rent Under Expiring Leases Without Future Step-Ups p.s.f. (3)				Current Annualized Contractual Rent Under Expiring Leases With Future Step-Ups (4)				Current Annualized Contractual Rent Under Expiring Leases With Future Step-Ups p.s.f. (4)				Percentage of Total Square Feet
2018 (5)		85,959				$14,144,762				$164.55				$14,144,762				$164.55			0.19	%
2019		2,592,707			137,259,806				52.94				138,310,784				53.35				5.78	%
2020		3,946,894			234,577,309				59.43				242,708,896				61.49				8.79	%
2021		3,542,532			212,591,474				60.01				220,729,635				62.31				7.89	%
2022		4,066,621			261,208,582				64.23				269,271,116				66.21				9.06	%
2023		2,255,750			141,070,158				62.54				152,977,171				67.82				5.03	%
2024		3,617,153			219,695,550				60.74				239,256,924				66.15				8.06	%
2025		2,804,390			171,282,622				61.08				191,383,737				68.24				6.25	%
2026		3,221,596			241,309,622				74.90				270,972,698				84.11				7.18	%
2027		1,861,920			127,425,562				68.44				147,493,704				79.22				4.15	%
Thereafter		12,725,917			943,306,135				74.12				1,221,121,708				95.96				28.35	%

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(1)	Includes 100% of unconsolidated joint venture properties. Does not include residential units or the hotel.

(2)	Does not include data for leases expiring in a particular year when leases for the same space have already been signed with replacement tenants with future commencement dates. In those cases, the data is included in the year in which the future lease with the replacement tenant expires.

(3)	Represents the monthly contractual base rent and recoveries from tenants under existing leases as of December 31, 2018 multiplied by twelve. This amount reflects total rent before any rent abatements and includes expense reimbursements, which may be estimates as of such date.

(4)	Represents the monthly contractual base rent under expiring leases with future contractual increases upon expiration and recoveries from tenants under existing leases as of December 31, 2018 multiplied by twelve. This amount reflects total rent before any rent abatements and includes expense reimbursements, which may be estimates as of such date.

(5)	Represents leases that expired on December 31, 2018.