Year	kg per kg of oil equivalent energy use
1971	1.470799224427293
1972	1.5290061904154217
1973	1.615815641985436
1974	1.64437469554843
1975	1.6595433766233025
1976	1.6227333408908815
1977	1.649206933079108
1978	1.6827121080136473
1979	1.6845254150267905
1980	1.6432890796713389
1981	1.5730079727162867
1982	1.550466812331856
1983	1.4640213717832655
1984	1.3934604746374473
1985	1.4011902766357411
1986	1.4688114776844445
1987	1.475340981843072
1988	1.468561862686027
1989	1.4716009717864926
1990	1.4140526146682306
1991	1.4362494622376956
1992	1.4455376976605323
1993	1.4543122022788635
1994	1.4298653088321922
1995	1.499117932044593
1996	1.5495414421204394
1997	1.5790674984633246
1998	1.5927433831416407
1999	1.6102566373699803
2000	1.668093031053344
2001	1.675617635067059
2002	1.6207707865424184
2003	1.5547060215003052
2004	1.555690639804199
2005	1.53488670561486
2006	1.4988951516288986
2007	1.4929090599491581
2008	1.4971460472445886
2009	1.4590338313152527
2010	1.4959147757121152
2011	1.5446627960233374
2012	1.6034693203994002
2013	1.6438968601283992
2014	1.6712091349785836