federal realty investment trust schedule iii summary of real estate and accumulated depreciation - continued three years ended december 31 , 2011 reconciliation of accumulated depreciation and amortization ( in thousands ) balance , december 31 , 2008................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2009................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2010................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2011................................................................................................................................... . $ 846258 103698 ( 11869 ) 938087 108261 ( 11144 ) 1035204 114180 ( 21796 ) $ 1127588 .
considering the years 2008-2010 , what is the value of the average deductions?\\n
federal realty investment trust schedule iii summary of real estate and accumulated depreciation - continued three years ended december 31 , 2011 reconciliation of accumulated depreciation and amortization ( in thousands ) balance , december 31 , 2008................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2009................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2010................................................................................................................................... . additions during period 2014depreciation and amortization expense .................................................................... . deductions during period 2014disposition and retirements of property ................................................................. . balance , december 31 , 2011................................................................................................................................... . $ 846258 103698 ( 11869 ) 938087 108261 ( 11144 ) 1035204 114180 ( 21796 ) $ 1127588 .