Year	kg per kg of oil equivalent energy use
1971	2.9868420037552768
1972	3.0071928167120023
1973	3.030434316148085
1974	3.140451433992341
1975	3.1322883982039382
1976	3.125647148112873
1977	2.99768320847548
1978	3.0237532506299
1979	3.0794379421790694
1980	3.014344402127904
1981	3.0601526032627895
1982	3.022563974459467
1983	3.0719327475782188
1984	2.924177231904761
1985	2.992696350993512
1986	3.031394322780422
1987	3.0535772883527583
1988	3.041867913727005
1989	3.09522156528292
1990	2.7729644845622357
1991	2.773593913241211
1992	2.6923344862853136
1993	2.5791944121722366
1994	2.6752020231956215
1995	2.5912075325434993
1996	2.597391657177997
1997	2.527054939381985
1998	2.4217114582574695
1999	2.3576463475880494
2000	2.4533738209941944
2001	2.555820965759766
2002	2.453864129393706
2003	2.5201000875887827
2004	2.500294733905752
2005	2.482406870813043
2006	2.4771787963009166
2007	2.425356839175579
2008	2.4032691123756114
2009	2.3084959675718815
2010	2.212461255521233
2011	2.3446907041546075
2012	2.3394519270680654
2013	2.257808282384499
2014	2.253500467898774