Concentration	12 Months Ended
Dec. 31, 2015
Concentration
Concentration	Note 7. Concentration Tenant and Credit Concentration We define annualized rental income as the annualized contractual base rents from our tenants pursuant to our lease agreements as of the measurement date, plus straight line rent adjustments and estimated recurring expense reimbursements to be paid to us, and excluding lease value amortization. The U.S. Government, 12 state governments, two municipal tenants, and the United Nations combined were responsible for approximately 92.8%, 93.0% and 92.6% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2015, 2014 and 2013, respectively. The U.S. Government is our largest tenant by annualized rental income and was responsible for approximately 67.0%, 69.0% and 69.0% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2015, 2014 and 2013, respectively. Geographic Concentration At December 31, 2015, our 71 properties (91 buildings), excluding one property (one building) classified as discontinued operations, were located in 31 states and the District of Columbia. Properties located in California, Virginia, the District of Columbia, Georgia, New York, Maryland and Massachusetts were responsible for approximately 11.4%, 10.4%, 10.2%, 8.6%, 8.6%, 8.4% and 5.6% of our annualized rental income as of December 31, 2015, respectively.

Concentration

12 Months Ended

Dec. 31, 2015

Note 7. Concentration

Tenant and Credit Concentration

We define annualized rental income as the annualized contractual base rents from our tenants pursuant to our lease agreements as of the measurement date, plus straight line rent adjustments and estimated recurring expense reimbursements to be paid to us, and excluding lease value amortization. The U.S. Government, 12 state governments, two municipal tenants, and the United Nations combined were responsible for approximately 92.8%, 93.0% and 92.6% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2015, 2014 and 2013, respectively. The U.S. Government is our largest tenant by annualized rental income and was responsible for approximately 67.0%, 69.0% and 69.0% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2015, 2014 and 2013, respectively.

Geographic Concentration

At December 31, 2015, our 71 properties (91 buildings), excluding one property (one building) classified as discontinued operations, were located in 31 states and the District of Columbia. Properties located in California, Virginia, the District of Columbia, Georgia, New York, Maryland and Massachusetts were responsible for approximately 11.4%, 10.4%, 10.2%, 8.6%, 8.6%, 8.4% and 5.6% of our annualized rental income as of December 31, 2015, respectively.