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.

Text: operating expenses millions 2010 2009 2008 % (  % ) change 2010 v 2009 % (  % ) change 2009 v 2008 . <table class='wikitable'><tr><td>1</td><td>millions</td><td>2010</td><td>2009</td><td>2008</td><td>% (  % ) change 2010 v 2009</td><td>% (  % ) change2009 v 2008</td></tr><tr><td>2</td><td>compensation and benefits</td><td>$ 4314</td><td>$ 4063</td><td>$ 4457</td><td>6% ( 6 % )</td><td>( 9 ) % (  % )</td></tr><tr><td>3</td><td>fuel</td><td>2486</td><td>1763</td><td>3983</td><td>41</td><td>-56 ( 56 )</td></tr><tr><td>4</td><td>purchased services and materials</td><td>1836</td><td>1644</td><td>1928</td><td>12</td><td>-15 ( 15 )</td></tr><tr><td>5</td><td>depreciation</td><td>1487</td><td>1427</td><td>1366</td><td>4</td><td>4</td></tr><tr><td>6</td><td>equipment and other rents</td><td>1142</td><td>1180</td><td>1326</td><td>-3 ( 3 )</td><td>-11 ( 11 )</td></tr><tr><td>7</td><td>other</td><td>719</td><td>687</td><td>840</td><td>5</td><td>-18 ( 18 )</td></tr><tr><td>8</td><td>total</td><td>$ 11984</td><td>$ 10764</td><td>$ 13900</td><td>11% ( 11 % )</td><td>( 23 ) % (  % )</td></tr></table> operating expenses increased $ 1.2 billion in 2010 versus 2009 . our fuel price per gallon increased 31% ( 31 % ) during the year , accounting for $ 566 million of the increase . wage and benefit inflation , depreciation , volume-related costs , and property taxes also contributed to higher expenses during 2010 compared to 2009 . cost savings from productivity improvements and better resource utilization partially offset these increases . operating expenses decreased $ 3.1 billion in 2009 versus 2008 . our fuel price per gallon declined 44% ( 44 % ) during 2009 , decreasing operating expenses by $ 1.3 billion compared to 2008 . cost savings from lower volume , productivity improvements , and better resource utilization also decreased operating expenses in 2009 . in addition , lower casualty expense resulting primarily from improving trends in safety performance decreased operating expenses in 2009 . conversely , wage and benefit inflation partially offset these reductions . compensation and benefits 2013 compensation and benefits include wages , payroll taxes , health and welfare costs , pension costs , other postretirement benefits , and incentive costs . general wage and benefit inflation increased costs by approximately $ 190 million in 2010 compared to 2009 . volume- related expenses and higher equity and incentive compensation also drove costs up during the year . workforce levels declined 1% ( 1 % ) in 2010 compared to 2009 as network efficiencies and ongoing productivity initiatives enabled us to effectively handle the 13% ( 13 % ) increase in volume levels with fewer employees . lower volume and productivity initiatives led to a 10% ( 10 % ) decline in our workforce in 2009 compared to 2008 , saving $ 516 million during the year . conversely , general wage and benefit inflation increased expenses , partially offsetting these savings . fuel 2013 fuel includes locomotive fuel and gasoline for highway and non-highway vehicles and heavy equipment . higher diesel fuel prices , which averaged $ 2.29 per gallon ( including taxes and transportation costs ) in 2010 compared to $ 1.75 per gallon in 2009 , increased expenses by $ 566 million . volume , as measured by gross ton-miles , increased 10% ( 10 % ) in 2010 versus 2009 , driving fuel expense up by $ 166 million . conversely , the use of newer , more fuel efficient locomotives , our fuel conservation programs and efficient network operations drove a 3% ( 3 % ) improvement in our fuel consumption rate in 2010 , resulting in $ 40 million of cost savings versus 2009 at the 2009 average fuel price . lower diesel fuel prices , which averaged $ 1.75 per gallon ( including taxes and transportation costs ) in 2009 compared to $ 3.15 per gallon in 2008 , reduced expenses by $ 1.3 billion in 2009 . volume , as measured by gross ton-miles , decreased 17% ( 17 % ) in 2009 , lowering expenses by $ 664 million compared to 2008 . our fuel consumption rate improved 4% ( 4 % ) in 2009 , resulting in $ 147 million of cost savings versus 2008 at the 2008 average fuel price . the consumption rate savings versus 2008 using the lower 2009 fuel price was $ 68 million . newer , more fuel efficient locomotives , reflecting locomotive acquisitions in recent years and the impact of a smaller fleet due to storage of some of our older locomotives ; increased use of 2010 operating expenses .
Question: what is the sum of operating expense for 2009 and 2010?

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