item 7 . management 2019s discussion and analysis of financial condition and results of operations executive summary international paper 2019s operating results in 2007 bene- fited from significantly higher paper and packaging price realizations . sales volumes were slightly high- er , with growth in overseas markets partially offset by lower volumes in north america as we continued to balance our production with our customers 2019 demand . operationally , our pulp and paper and containerboard mills ran very well in 2007 . however , input costs for wood , energy and transportation costs were all well above 2006 levels . in our forest products business , earnings decreased 31% ( 31 % ) reflect- ing a sharp decline in harvest income and a smaller drop in forestland and real estate sales , both reflect- ing our forestland divestitures in 2006 . interest expense decreased over 40% ( 40 % ) , principally due to lower debt balances and interest rates from debt repayments and refinancings . looking forward to the first quarter of 2008 , we expect demand for north american printing papers and packaging to remain steady . however , if the economic downturn in 2008 is greater than expected , this could have a negative impact on sales volumes and earnings . some slight increases in paper and packaging price realizations are expected as we implement our announced price increases . however , first quarter earnings will reflect increased planned maintenance expenses and continued escalation of wood , energy and transportation costs . as a result , excluding the impact of projected reduced earnings from land sales and the addition of equity earnings contributions from our recent investment in ilim holding s.a . in russia , we expect 2008 first-quarter earnings to be lower than in the 2007 fourth quarter . results of operations industry segment operating profits are used by inter- national paper 2019s management to measure the earn- ings performance of its businesses . management believes that this measure allows a better under- standing of trends in costs , operating efficiencies , prices and volumes . industry segment operating profits are defined as earnings before taxes and minority interest , interest expense , corporate items and corporate special items . industry segment oper- ating profits are defined by the securities and exchange commission as a non-gaap financial measure , and are not gaap alternatives to net earn- ings or any other operating measure prescribed by accounting principles generally accepted in the united states . international paper operates in six segments : print- ing papers , industrial packaging , consumer pack- aging , distribution , forest products , and specialty businesses and other . the following table shows the components of net earnings for each of the last three years : in millions 2007 2006 2005 .
what was the percentage change in industry segment operating profits from 2006 to 2007?
* corporate special items include restructuring and other charg- es , net ( gains ) losses on sales and impairments of businesses , gains on transformation plan forestland sales , goodwill impairment charges , insurance recoveries and reversals of reserves no longer required . industry segment operating profits of $ 2.4 billion were $ 349 million higher in 2007 than in 2006 due principally to the benefits from higher average price realizations ( $ 461 million ) , the net impact of cost reduction initiatives , improved operating perform- ance and a more favorable mix of products sold ( $ 304 million ) , higher sales volumes ( $ 17 million ) , lower special item costs ( $ 115 million ) and other items ( $ 4 million ) . these benefits more than offset the impacts of higher energy , raw material and freight costs ( $ 205 million ) , higher costs for planned mill maintenance outages ( $ 48 million ) , lower earn- ings from land sales ( $ 101 million ) , costs at the pensacola mill associated with the conversion of a machine to the production of linerboard ( $ 52 million ) and reduced earnings due to net acquisitions and divestitures ( $ 146 million ) . segment operating profit ( in millions ) $ 2074 ( $ 205 ) ( $ 48 ) $ 17 ( $ 244 ) $ 2423$ 4 ( $ 52 ) ( $ 101 ) $ 461 $ 1000 $ 1500 $ 2000 $ 2500 $ 3000 .