Year	kg per kg of oil equivalent energy use
1990	3.467640135653759
1991	3.452148200145501
1992	3.1803565775808926
1993	3.205960417748543
1994	3.472752837833358
1995	3.428348320189331
1996	3.4219080640597435
1997	3.3647037367193766
1998	3.4198128310131333
1999	3.3726153229648164
2000	3.30621140410525
2001	3.48902780316605
2002	3.335555718222699
2003	3.3014787828906687
2004	3.247872770774097
2005	3.3420347635885315
2006	3.195342506955923
2007	3.242693279890046
2008	3.1716078197679227
2009	3.182631922934841
2010	3.031846894857425
2011	3.088461680168007
2012	3.083117886541262
2013	3.051183981580328
2014	2.9661202727458154