Year kg per kg of oil equivalent energy use 1990 2.3910198489023142 1991 2.3244625356102255 1992 2.2880825295153637 1993 2.2285744173301225 1994 2.1406759215641262 1995 1.9580869316625484 1996 1.992812603953599 1997 1.9250394599237475 1998 1.878105631313773 1999 1.8981490909374317 2000 1.8085565865516986 2001 1.790119222913137 2002 1.8043761645591063 2003 1.7552663772828292 2004 1.7169049116323463 2005 1.7049036961296258 2006 1.7487867791719494 2007 1.7784545959290694 2008 1.7683361853477975 2009 1.6716270382039458 2010 1.8904266972625867 2011 1.855909969102623 2012 1.7143514542773184 2013 1.7167508565895466 2014 1.677360995043721