Year	kg per kg of oil equivalent energy use
1971	0.5503936003498672
1972	0.556291665137139
1973	0.5921630453471824
1974	0.5887892651063376
1975	0.5608924346486188
1976	0.5434082177917255
1977	0.5425980250292971
1978	0.5597384338820467
1979	0.5602144631772453
1980	0.5867705466392464
1981	0.5729587101116601
1982	0.5888429840997019
1983	0.5751147974029398
1984	0.5368715971987829
1985	0.5575238294400422
1986	0.4747215987511665
1987	0.4916696171086291
1988	0.5365457341251512
1989	0.574630772246161
1990	0.44221004762227356
1991	0.4168946193283171
1992	0.4156687282501713
1993	0.44911217500925726
1994	0.4679653495269012
1995	0.4733479427277534
1996	0.4703982264881488
1997	0.49066035677447856
1998	0.5083516523511155
1999	0.5065566369873642
2000	0.5064502224962636
2001	0.5190385794751735
2002	0.5334919620029579
2003	0.5422827723540858
2004	0.5623235185939893
2005	0.5764916373415161
2006	0.6049060201376959
2007	0.6384820141854596
2008	0.6360444022896596
2009	0.6449009642035815
2010	0.6541777987925338
2011	0.6572366090123534
2012	0.658282777351981
2013	0.6663083313585114
2014	0.6983498805669517