Year	kg per kg of oil equivalent energy use
1971	0.26548944865870633
1972	0.3358400970449334
1973	0.3225563083064796
1974	0.33691127623137324
1975	0.3568044272965153
1976	0.2159257437772181
1977	0.23791242414727762
1978	0.27980478646207063
1979	0.2778954515933708
1980	0.38227570145281137
1981	0.3177424120899996
1982	0.3517480815485053
1983	0.31663976401804406
1984	0.3414640611724724
1985	0.4825425368064595
1986	0.44032802633251866
1987	0.3414072935449486
1988	0.34186012626889367
1989	0.3871541173228149
1990	0.22873446637151895
1991	0.19565225124594912
1992	0.20829837585127498
1993	0.23743341264739953
1994	0.22131593347464354
1995	0.24904847241246758
1996	0.48819339153528457
1997	0.5556852652433656
1998	0.5905882940857125
1999	0.6184146461492366
2000	0.7716866649518074
2001	0.8726392499855351
2002	0.9372808774363776
2003	0.997691057837576
2004	1.0158582295558531
2005	1.1123181229831733
2006	1.2987312446931738
2007	1.3691828442325278
2008	1.3272242371282896
2009	1.3667689610840166
2010	1.3905007992642389
2011	1.326660956874195
2012	1.2189627398579215
2013	1.2351310641367639
2014	1.2851437844988802