Year kg per kg of oil equivalent energy use 2000 0.45605129011464585 2001 0.43633132620923276 2002 0.44573097970395825 2003 0.4633999409774812 2004 0.46063549039021073 2005 0.4384340520190465 2006 0.42189416981634104 2007 0.44087988872621736 2008 0.4416130996823467 2009 0.5231141372079945 2010 0.6147599833431455 2011 0.7284875307217658 2012 0.8303487640544217 2013 0.6241970872662399 2014 0.6860017531155913