Year	kg per kg of oil equivalent energy use
1971	2.157772313842511
1972	2.690504847657069
1973	2.7139442379876377
1974	2.3816703547329303
1975	2.697997576571524
1976	2.4176353549879743
1977	3.008779003539797
1978	3.0608600999595654
1979	2.691881204372194
1980	2.8117667105248616
1981	2.7472820491668837
1982	2.8102450126565213
1983	2.441037744244741
1984	2.559804519547211
1985	2.4496958864469716
1986	2.475636163348808
1987	2.67308180724971
1988	2.4916930856219976
1989	2.380758317293358
1990	2.0516989939797727
1991	2.00858354106486
1992	2.1643746403733664
1993	2.1875652231693117
1994	2.1052518870111157
1995	2.105436333020317
1996	2.2041400812685272
1997	1.9897960169306528
1998	2.0370308836734536
1999	2.0479770096354337
2000	1.9930039036771674
2001	2.0017264432582
2002	2.0282941139540864
2003	1.994013297048805
2004	1.983151946270629
2005	1.9939511036952828
2006	2.0230765599606175
2007	1.9772408493319271
2008	1.9634118946457115
2009	2.0183262060764107
2010	2.0510739519529215
2011	2.0544687576312506
2012	2.1159622153017437
2013	2.0989085091911175
2014	2.134514534970369