Year	kg per kg of oil equivalent energy use
1971	2.8618284789965958
1972	2.4524946291155167
1973	2.84526331236581
1974	2.783942350054879
1975	3.053389117906438
1976	2.994573497102946
1977	3.1352184750171435
1978	3.6940929859524614
1979	3.3408927074503434
1980	3.709725414568569
1981	3.1931448799772615
1982	2.717257590255113
1983	3.2225983715774973
1984	2.5644519810846282
1985	2.926029748615501
1986	2.5971144232042334
1987	2.991810690508571
1988	2.4686643495856075
1989	2.9246504103627964
1990	2.6825893487197368
1991	2.647512036341038
1992	2.770093459214537
1993	2.8194616048294123
1994	2.7854060676647596
1995	2.7106787627063067
1996	2.6787336109062387
1997	2.7263476010215504
1998	2.77155619173352
1999	2.7684118109657403
2000	2.6381404833409032
2001	2.6351494427756905
2002	2.8734794387828333
2003	2.8496682921526215
2004	2.8119734200673276
2005	2.8436960832125795
2006	2.8984727019629823
2007	2.8725619668015963
2008	2.7323296802861847
2009	2.6093276842051236
2010	2.797409927514172
2011	2.6644705819659515
2012	2.567201277606892
2013	2.6339034101057104
2014	2.634763713322042