Year	kg per kg of oil equivalent energy use
1971	1.0617310926223413
1972	1.1613381996331116
1973	1.258950314762032
1974	1.3725216764679797
1975	1.185549840634002
1976	1.335758381066889
1977	1.2024084569920697
1978	1.1513359617689907
1979	1.4017313157554927
1980	1.3201612106178195
1981	1.152608897611258
1982	1.107833105387313
1983	1.074907699276251
1984	1.1345093236259982
1985	1.130104805689377
1986	1.1063997399321492
1987	1.0412398056398269
1988	1.1888183335496751
1989	1.0331880932480382
1990	1.0530086792651305
1991	0.9861037904241575
1992	1.0931930099851488
1993	1.1598166295452224
1994	1.1754946623306755
1995	1.17396774383816
1996	1.1870358675711383
1997	1.2065232971386264
1998	1.0559806685339799
1999	0.9757344308650518
2000	0.9913672109385159
2001	1.0330114668130215
2002	1.003662305619897
2003	0.9762988963713919
2004	1.0037855648456457
2005	1.087512437002837
2006	1.0597463526002224
2007	1.0174021508317495
2008	1.0146304456342228
2009	1.0216341882387097
2010	1.0750147140386248
2011	1.0973714262599346
2012	1.1017672749924257
2013	1.1491885599489526
2014	1.1982276431543275