Item 6. SELECTED FINANCIAL DATA



	Year Ended December 31,
(In thousands, except per share amounts)
	2015		2014		2013		2012		2011
Operating Data:
Revenue from operations	$	2,972,442	$	2,787,897	$	2,337,648	$	2,134,579	$	1,903,800
Depreciation and amortization expense	165,343		146,466		127,072		110,743		90,820
Total operating expenses	2,474,202		2,346,590		1,999,210		1,849,325		1,669,728
Operating income	498,240		441,307		338,438		285,254		234,072
Interest expense, net (1)	5,001		6,502		9,473		11,428		13,887
Provision for income taxes	185,327		165,000		122,573		103,646		80,614
Net income	304,690		267,514		206,113		169,452		139,470

Per Share Data:
Diluted earnings per share	$	3.57	$	3.10	$	2.39	$	1.97	$	1.63

Balance Sheet Data:
Cash and cash equivalents	$	11,472	$	34,787	$	30,174	$	12,857	$	75,850
Current assets (2)	381,730		403,772		309,730		254,974		312,386
Total assets (2)	2,466,504		2,206,866		1,908,840		1,692,460		1,493,608
Current liabilities	285,402		255,638		232,122		225,139		204,810
Long-term debt (including current maturities)	133,805		155,714		191,429		240,407		269,185
Shareholders’ equity	1,684,637		1,494,064		1,232,082		1,025,969		856,519


(1)	For the purpose of this table, interest expense is presented net of interest income.


(2)	Prior-year balance sheets have been adjusted to reflect the adoption of Accounting Standards Update ("ASU") 2015-17 in order to conform to the current period presentation. For additional information regarding ASU 2015-17, please refer to "Recent Accounting Pronouncements" included in Note 1 of Item 8, "Financial Statements and Supplementary Data" in this report.