Concentration	6 Months Ended
Jun. 30, 2013
Concentration
Concentration	Note 5. Concentration Tenant and Credit Concentration We define annualized rental income as the annualized contractual base rents from our tenants pursuant to our lease agreements with them 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, 10 state governments and the United Nations combined were responsible for approximately 94.0% and 92.7% of our annualized rental income as of June 30, 2013 and 2012, respectively. The U.S. Government is our largest tenant by annualized rental income and was responsible for approximately 71.5% and 67.7% of our annualized rental income as of June 30, 2013 and 2012, respectively. Geographic Concentration At June 30, 2013, our 82 properties were located in 31 states and the District of Columbia. Properties located in Maryland, California, the District of Columbia, Georgia, New York and Massachusetts were responsible for approximately 12.3%, 12.2%, 10.9%, 9.6%, 8.8% and 6.0% of our annualized rental income as of June 30, 2013, respectively.

Concentration

6 Months Ended

Jun. 30, 2013

Note 5. Concentration

Tenant and Credit Concentration

We define annualized rental income as the annualized contractual base rents from our tenants pursuant to our lease agreements with them 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, 10 state governments and the United Nations combined were responsible for approximately 94.0% and 92.7% of our annualized rental income as of June 30, 2013 and 2012, respectively. The U.S. Government is our largest tenant by annualized rental income and was responsible for approximately 71.5% and 67.7% of our annualized rental income as of June 30, 2013 and 2012, respectively.

Geographic Concentration

At June 30, 2013, our 82 properties were located in 31 states and the District of Columbia. Properties located in Maryland, California, the District of Columbia, Georgia, New York and Massachusetts were responsible for approximately 12.3%, 12.2%, 10.9%, 9.6%, 8.8% and 6.0% of our annualized rental income as of June 30, 2013, respectively.