[["", "2009", "2008", "2007", "% (  % ) change 2009 v 2008", "% (  % ) change 2008 v 2007"], ["average train speed ( miles per hour )", "27.3", "23.5", "21.8", "16 % (  % )", "8 % (  % )"], ["average terminal dwell time ( hours )", "24.8", "24.9", "25.1", "-", "( 1 ) % (  % )"], ["average rail car inventory ( thousands )", "283.1", "300.7", "309.9", "( 6 ) % (  % )", "( 3 ) % (  % )"], ["gross ton-miles ( billions )", "846.5", "1020.4", "1052