operating expenses millions 2010 2009 2008 % (  % ) change 2010 v 2009 % (  % ) change 2009 v 2008 .

2010: compensation and benefits: 4314
fuel: 2486
purchased services and materials: 1836
depreciation: 1487
equipment and other rents: 1142
other: 719
total: 11984
2009: compensation and benefits: 4063
fuel: 1763
purchased services and materials: 1644
depreciation: 1427
equipment and other rents: 1180
other: 687
total: 10764
2008: compensation and benefits: 4457
fuel: 3983
purchased services and materials: 1928
depreciation: 1366
equipment and other rents: 1326
other: 840
total: 13900
% (  % ) change 2010 v 2009: compensation and benefits: -6
fuel: 41
purchased services and materials: 12
depreciation: 4
equipment and other rents: -3
other: 5
total: -11
% (  % ) change2009 v 2008: compensation and benefits: -9
fuel: -56
purchased services and materials: -15
depreciation: 4
equipment and other rents: -11
other: -18
total: -23

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 .

Questions:
what are the operating expenses for compensation and benefits in 2008?
what about the total operating expenses in 2008?
what portion of is related to compensation and benefits?
what is the sum of total operating expenses for 2009 and 2010?
what about the sum for three years if 2008 is inlcuded?
what is the yearly average for this period?

Answers:
4457
13900
32.1%
22748
36648
12216