Please answer the given financial question based on the context.
Context: federal realty investment trust schedule iii summary of real estate and accumulated depreciation 2014continued three years ended december 31 , 2007 reconciliation of accumulated depreciation and amortization ( in thousands ) .
|balance december 31 2004|$ 595338|
|additions during period 2014depreciation and amortization expense|83656|
|deductions during period 2014disposition and retirements of property|-15244 ( 15244 )|
|balance december 31 2005|$ 663750|
|additions during period 2014depreciation and amortization expense|89564|
|deductions during period 2014disposition and retirements of property|-12807 ( 12807 )|
|balance december 31 2006|$ 740507|
|additions during period 2014depreciation and amortization expense|96454|
|deductions during period 2014disposition and retirements of property|-80258 ( 80258 )|
|balance december 31 2007|$ 756703|
.
Question: what is the variation of the additions during 2005 and 2006 , in thousands of dollars?


Answer: The answer is:5908.0