$ 190 million , or 30% ( 30 % ) of pre-tax earnings before equity earnings . during the 2009 second quarter , in connection with the evaluation of the company 2019s etienne mill in france , the company determined that the future realization of previously recorded deferred tax assets in france , including net operating loss carryforwards , no longer met the 201cmore likely than not 201d standard for asset recognition . accordingly , a charge of $ 156 million , before and after taxes , was recorded to establish a valuation allowance for 100% ( 100 % ) of these assets . additionally in 2009 , as a result of agree- ments on the 2004 and 2005 u.s . federal income tax audits , and related state income tax effects , a $ 26 million credit was recorded . the 2008 income tax provision of $ 162 million included a $ 207 million benefit related to special items which included a $ 175 million tax benefit related to restructuring and other charges , a $ 23 mil- lion tax benefit for the impairment of certain non-u.s . assets , a $ 29 million tax expense for u.s . taxes on a gain in the company 2019s ilim joint venture , a $ 40 million tax benefit related to the restructuring of the company 2019s international operations , and $ 2 mil- lion of other expense . excluding the impact of spe- cial items , the tax provision was $ 369 million , or 31.5% ( 31.5 % ) of pre-tax earnings before equity earnings . the company recorded an income tax provision for 2007 of $ 415 million , including a $ 41 million benefit related to the effective settlement of tax audits , and $ 8 million of other tax benefits . excluding the impact of special items , the tax provision was $ 423 million , or 30% ( 30 % ) of pre-tax earnings before equity earnings . international paper has u.s . federal and non-u.s . net operating loss carryforwards of approximately $ 452 million that expire as follows : 2010 through 2019 2013 $ 8 million , years 2020 through 2029 2013 $ 29 million and indefinite carryforwards of $ 415 million . international paper has tax benefits from net operating loss carryforwards for state taxing jurisdictions of approx- imately $ 204 million that expire as follows : 2010 through 2019 2013 $ 75 million and 2020 through 2029 2013 $ 129 million . international paper also has approx- imately $ 273 million of u.s . federal , non-u.s . and state tax credit carryforwards that expire as follows : 2010 through 2019 2013 $ 54 million , 2020 through 2029 2013 $ 32 million , and indefinite carryforwards 2013 $ 187 mil- lion . further , international paper has $ 2 million of state capital loss carryforwards that expire in 2010 through 2019 . deferred income taxes are not provided for tempo- rary differences of approximately $ 3.5 billion , $ 2.6 billion and $ 3.7 billion as of december 31 , 2009 , 2008 and 2007 , respectively , representing earnings of non-u.s . subsidiaries intended to be permanently reinvested . computation of the potential deferred tax liability associated with these undistributed earnings and other basis differences is not practicable . note 11 commitments and contingent liabilities certain property , machinery and equipment are leased under cancelable and non-cancelable agree- ments . unconditional purchase obligations have been entered into in the ordinary course of business , prin- cipally for capital projects and the purchase of cer- tain pulpwood , logs , wood chips , raw materials , energy and services , including fiber supply agree- ments to purchase pulpwood that were entered into concurrently with the company 2019s 2006 trans- formation plan forestland sales . at december 31 , 2009 , total future minimum commitments under existing non-cancelable operat- ing leases and purchase obligations were as follows : in millions 2010 2011 2012 2013 2014 thereafter obligations $ 177 $ 148 $ 124 $ 96 $ 79 $ 184 purchase obligations ( a ) 2262 657 623 556 532 3729 .
what was the sum of the temporary differences between 2007 and 2009 in billions
( a ) includes $ 2.8 billion relating to fiber supply agreements entered into at the time of the company 2019s 2006 transformation plan forestland sales . rent expense was $ 216 million , $ 205 million and $ 168 million for 2009 , 2008 and 2007 , respectively . in connection with sales of businesses , property , equipment , forestlands and other assets , interna- tional paper commonly makes representations and warranties relating to such businesses or assets , and may agree to indemnify buyers with respect to tax and environmental liabilities , breaches of representations and warranties , and other matters . where liabilities for such matters are determined to be probable and subject to reasonable estimation , accrued liabilities are recorded at the time of sale as a cost of the transaction . in may 2008 , a recovery boiler at the company 2019s vicksburg , mississippi facility exploded , resulting in one fatality and injuries to employees of contractors .