Year	kg per kg of oil equivalent energy use
1971	2.9399879137154987
1972	2.7865069317054134
1973	2.7455127885931807
1974	2.771205310293315
1975	2.780854998153506
1976	2.9094399044246875
1977	2.8177121036026613
1978	2.909193839183135
1979	2.8687575799010943
1980	2.8224300297581646
1981	2.801642190646363
1982	2.868076665044196
1983	2.7824150321732417
1984	2.6551652883887327
1985	2.6561886622122555
1986	2.787582812213579
1987	2.765634192843521
1988	2.7296896229634284
1989	3.0794610758595717
1990	2.1644416295653315
1991	2.203311547220817
1992	2.2130406459787437
1993	2.2595942470879193
1994	2.3946107022878684
1995	2.326007706680017
1996	2.421066479932906
1997	2.4640953862239323
1998	2.5612293022012724
1999	2.404975207645861
2000	2.563284571302289
2001	2.4647562110056693
2002	2.490999810198553
2003	2.4616611100463404
2004	2.4781581017961103
2005	2.4205990849218475
2006	2.4614655248603285
2007	2.5476129977462048
2008	2.6572835389831413
2009	2.5669324609528275
2010	2.683295876062515
2011	2.619364653105246
2012	2.507514562790781
2013	2.445944081395497
2014	2.4381384606447467
2015	2.522794418326825