Year kg per kg of oil equivalent energy use 1971 2.8886982021219616 1972 3.0017414527059074 1973 3.0157733481501476 1974 2.9574334341457624 1975 2.9719280444168437 1976 2.6410153300301014 1977 3.0719272680777143 1978 2.6421715325344644 1979 2.642390046209368 1980 2.4980311347536657 1981 2.6940361057382334 1982 3.4222544069393583 1983 3.782188092151192 1984 3.572663477181059 1985 3.4595067527034646 1986 3.002857589562832 1987 2.9911220436529233 1988 3.8699139060736587 1989 4.106167308558174 1990 2.8763060451047777 1991 2.9110974010185533 1992 2.86462679666577 1993 2.94271309601335 1994 2.930206739475501 1995 3.0163490655214518 1996 3.036784449598949 1997 3.071966675732111 1998 3.1495623465072904 1999 3.1548014577665078 2000 3.193362045740683 2001 3.2106957800165836 2002 3.2217690573187916 2003 3.327288409015289 2004 3.381884560845834 2005 3.427034023030541 2006 3.385320142195961 2007 3.5620365950149004 2008 3.4360249353029277 2009 3.2970427992856006 2010 3.273534881489571 2011 3.337310373646404 2012 3.2742650160540783 2013 3.2864876850752873 2014 3.328157829945013