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.


at december 31 , 2009 , aon had domestic federal operating loss carryforwards of $ 7 million that will expire at various dates from 2010 to 2024 , state operating loss carryforwards of $ 513 million that will expire at various dates from 2010 to 2028 , and foreign operating and capital loss carryforwards of $ 453 million and $ 252 million , respectively , nearly all of which are subject to indefinite carryforward . unrecognized tax benefits the following is a reconciliation of the company 2019s beginning and ending amount of unrecognized tax benefits ( in millions ) : . <table class='wikitable'><tr><td>1</td><td>-</td><td>2009</td><td>2008</td></tr><tr><td>2</td><td>balance at january 1</td><td>$ 86</td><td>$ 70</td></tr><tr><td>3</td><td>additions based on tax positions related to the current year</td><td>2</td><td>5</td></tr><tr><td>4</td><td>additions for tax positions of prior years</td><td>5</td><td>12</td></tr><tr><td>5</td><td>reductions for tax positions of prior years</td><td>-11 ( 11 )</td><td>-11 ( 11 )</td></tr><tr><td>6</td><td>settlements</td><td>-10 ( 10 )</td><td>-4 ( 4 )</td></tr><tr><td>7</td><td>lapse of statute of limitations</td><td>-3 ( 3 )</td><td>-1 ( 1 )</td></tr><tr><td>8</td><td>acquisitions</td><td>6</td><td>21</td></tr><tr><td>9</td><td>foreign currency translation</td><td>2</td><td>-6 ( 6 )</td></tr><tr><td>10</td><td>balance at december 31</td><td>$ 77</td><td>$ 86</td></tr></table> as of december 31 , 2009 , $ 61 million of unrecognized tax benefits would impact the effective tax rate if recognized . aon does not expect the unrecognized tax positions to change significantly over the next twelve months . the company recognizes penalties and interest related to unrecognized income tax benefits in its provision for income taxes . aon accrued potential penalties of less than $ 1 million during each of 2009 , 2008 and 2007 . aon accrued interest of $ 2 million during 2009 and less than $ 1 million during both 2008 and 2007 . as of december 31 , 2009 and 2008 , aon has recorded a liability for penalties of $ 5 million and $ 4 million , respectively , and for interest of $ 18 million and $ 14 million , respectively . aon and its subsidiaries file income tax returns in the u.s . federal jurisdiction as well as various state and international jurisdictions . aon has substantially concluded all u.s . federal income tax matters for years through 2006 . material u.s . state and local income tax jurisdiction examinations have been concluded for years through 2002 . aon has concluded income tax examinations in its primary international jurisdictions through 2002. .
Question: what was the change in value of unrecognized tax benefits from 2008 to 2009?

-9.0