properties which are typically concentrated in large office parks primarily located adjacent to government demand drivers and/or in growth corridors. As of September 30, 2010, the Company owned 269 office properties totaling 21.0million rentable square feet, which includes 20 properties totaling 1.1 million square feet held through joint ventures. The Company's portfolio primarily consists of technically sophisticated buildings in visually appealing settings that are environmentally sensitive, sustainable and meet unique customer requirements.