Year	kg per kg of oil equivalent energy use
1971	3.1332061177408788
1972	3.1802544224746168
1973	3.1611945094259037
1974	3.1786606429904305
1975	3.188680417198198
1976	3.2055408228020994
1977	3.179290959836893
1978	3.172156089816439
1979	3.1851522333893647
1980	3.2145745553261884
1981	3.175473363419874
1982	3.207659566150132
1983	3.193034013605442
1984	3.3136669047237324
1985	3.480793513946582
1986	2.5868114220421585
1987	3.076740167873263
1988	3.0973189779314927
1989	3.1209587449825755
1990	3.3393066620607263
1991	3.289473684210526
1992	3.2665619961854984
1993	3.3061468446887514
1994	3.2567330685561773
1995	3.3558655736133085
1996	3.324925475808301
1997	3.151575468749003
1998	3.431038301679471
1999	3.1995581688968424
2000	3.1531404835111476
2001	3.165598965650073
2002	3.163780171825992
2003	3.161099820507665
2004	3.1353481562946937
2005	2.974501033128221
2006	3.1805623234187803
2007	3.089646491997131
2008	3.2513444667974376
2009	3.2244472192675495
2010	3.0930764241638804
2011	3.0972848742827734
2012	3.0864759961003343
2013	3.085503601056102
2014	3.035520759732719