Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.


federal realty investment trust schedule iii summary of real estate and accumulated depreciation 2014continued three years ended december 31 , 2009 reconciliation of accumulated depreciation and amortization ( in thousands ) . <table class='wikitable'><tr><td>1</td><td>balance december 31 2006</td><td>$ 740507</td></tr><tr><td>2</td><td>additions during period 2014depreciation and amortization expense</td><td>96454</td></tr><tr><td>3</td><td>deductions during period 2014disposition and retirements of property</td><td>-80258 ( 80258 )</td></tr><tr><td>4</td><td>balance december 31 2007</td><td>756703</td></tr><tr><td>5</td><td>additions during period 2014depreciation and amortization expense</td><td>101321</td></tr><tr><td>6</td><td>deductions during period 2014disposition and retirements of property</td><td>-11766 ( 11766 )</td></tr><tr><td>7</td><td>balance december 31 2008</td><td>846258</td></tr><tr><td>8</td><td>additions during period 2014depreciation and amortization expense</td><td>103.698</td></tr><tr><td>9</td><td>deductions during period 2014disposition and retirements of property</td><td>-11869 ( 11869 )</td></tr><tr><td>10</td><td>balance december 31 2009</td><td>$ 938087</td></tr></table> .
Question: for the years of 2006 and 2007, what was the combined total of additions, in thousands?
Answer: 197775.0
Question: and what were those additions in 2008?
Answer: 103.698
Question: including, then, 2008, what becomes that total of additions?

301473.0