Item 7A. Quantitative and Qualitative Disclosures About Market Risk

We face market risk exposure in the form of interest rate risk. This market risk arises from our debt obligations. Our primary market risk exposure is interest rate risk with respect to our indebtedness.

At December 31, 2017, we had $4,816.9 million aggregate principal amount of outstanding indebtedness. Approximately $2,500.0 million of our indebtedness has variable interest rates. A one percent increase or decrease in the annual interest rate on our variable rate borrowings of $2,500.0 million would increase or decrease our annual cash interest expense by approximately $25.0 million.

We may manage, or hedge, interest rate risks related to our borrowings by means of interest rate swap agreements. We also expect to manage our exposure to interest rate risk by maintaining a mix of fixed and variable rates for our indebtedness. However, the REIT provisions of the Code substantially limit our ability to hedge our assets and liabilities.