{"pre_text": ["intermodal 2013 decreased volumes and fuel surcharges reduced freight revenue from intermodal shipments in 2009 versus 2008 .", "volume from international traffic decreased 24% ( 24 % ) in 2009 compared to 2008 , reflecting economic conditions , continued weak imports from asia , and diversions to non-uprr served ports .", "additionally , continued weakness in the domestic housing and automotive sectors translated into weak demand in large sectors of the international intermodal market , which also contributed to the volume decline .", "conversely , domestic traffic increased 8% ( 8 % ) in 2009 compared to 2008 .", "a new contract with hub group , inc. , which included additional shipments , was executed in the second quarter of 2009 and more than offset the impact of weak market conditions in the second half of 2009 .", "price increases and fuel surcharges generated higher revenue in 2008 , partially offset by lower volume levels .", "international traffic declined 11% ( 11 % ) in 2008 , reflecting continued softening of imports from china and the loss of a customer contract .", "notably , the peak intermodal shipping season , which usually starts in the third quarter , was particularly weak in 2008 .", "additionally , continued weakness in domestic housing and automotive sectors translated into weak demand in large sectors of the international intermodal market , which also contributed to lower volumes .", "domestic traffic declined 3% ( 3 % ) in 2008 due to the loss of a customer contract and lower volumes from less-than-truckload shippers .", "additionally , the flood-related embargo on traffic in the midwest during the second quarter hindered intermodal volume levels in 2008 .", "mexico business 2013 each of our commodity groups include revenue from shipments to and from mexico .", "revenue from mexico business decreased 26% ( 26 % ) in 2009 versus 2008 to $ 1.2 billion .", "volume declined in five of our six commodity groups , down 19% ( 19 % ) in 2009 , driven by 32% ( 32 % ) and 24% ( 24 % ) reductions in industrial products and automotive shipments , respectively .", "conversely , energy shipments increased 9% ( 9 % ) in 2009 versus 2008 , partially offsetting these declines .", "revenue from mexico business increased 13% ( 13 % ) to $ 1.6 billion in 2008 compared to 2007 .", "price improvements and fuel surcharges contributed to these increases , partially offset by a 4% ( 4 % ) decline in volume in 2008 compared to 2007 .", "operating expenses millions of dollars 2009 2008 2007 % (  % ) change 2009 v 2008 % (  % ) change 2008 v 2007 ."], "post_text": ["2009 intermodal revenue international domestic ."], "table": [["millions of dollars", "2009", "2008", "2007", "% (  % ) change 2009 v 2008", "% (  % ) change 2008 v 2007"], ["compensation and benefits", "$ 4063", "$ 4457", "$ 4526", "( 9 ) % (  % )", "( 2 ) % (  % )"], ["fuel", "1763", "3983", "3104", "-56 ( 56 )", "28"], ["purchased services and materials", "1614", "1902", "1856", "-15 ( 15 )", "2"], ["depreciation", "1444", "1387", "1321", "4", "5"], ["equipment and other rents", "1180", "1326", "1368", "-11 ( 11 )", "-3 ( 3 )"], ["other", "687", "840", "733", "-18 ( 18 )", "15"], ["total", "$ 10751", "$ 13895", "$ 12908", "( 23 ) % (  % )", "8% ( 8 % )"]], "table_ori": [["<i>Millions of Dollars</i>", "<i>2009</i>", "<i>2008</i>", "<i>2007</i>", "<i>% Change 2009 v 2008</i>", "% Change 2008 v 2007"], ["Compensation and benefits", "$4,063", "$4,457", "$4,526", "(9)%", "(2)%"], ["Fuel", "1,763", "3,983", "3,104", "(56)", "28"], ["Purchased services and materials", "1,614", "1,902", "1,856", "(15)", "2"], ["Depreciation", "1,444", "1,387", "1,321", "4", "5"], ["Equipment and other rents", "1,180", "1,326", "1,368", "(11)", "(3)"], ["Other", "687", "840", "733", "(18)", "15"], ["Total", "$10,751", "$13,895", "$12,908", "(23)%", "8%"]]}

Question: what was the average yearly decline in international traffic in 2008 and in 2009?
Evidence:
text_6: international traffic declined 11% ( 11 % ) in 2008 , reflecting continued softening of imports from china and the loss of a customer contract .
text_1: volume from international traffic decreased 24% ( 24 % ) in 2009 compared to 2008 , reflecting economic conditions , continued weak imports from asia , and diversions to non-uprr served ports .
Program: add(11%, 24%), divide(#0, const_2)
Answer:
str_answer: 17.5%
exe_answer: 0.175