Year	kg per kg of oil equivalent energy use
1971	3.5051148892689543
1972	3.6242222839090648
1973	3.487901499013568
1974	3.3325278326214436
1975	2.7701312188645755
1976	2.4001557842977634
1977	2.4925918360267185
1978	2.4889142075153567
1979	2.6783908239368595
1980	2.7797824947665313
1981	2.6263913775607026
1982	2.6775332191926795
1983	2.475966824587076
1984	2.5403514733791086
1985	2.7871923837469432
1986	2.881066493312828
1987	2.9165731107459276
1988	3.1594245714631874
1989	2.884166790025381
1990	2.6048613300353245
1991	2.476257110411828
1992	2.264810558380341
1993	2.556981819822116
1994	2.2097918233095886
1995	2.4966315542716333
1996	2.6165373130178833
1997	2.7348785440700136
1998	2.532217606001501
1999	2.5550566812507465
2000	2.6210896512714235
2001	2.587472846989457
2002	2.527903703642864
2003	2.6076325347645946
2004	2.5299901494512715
2005	2.79851955704641
2006	2.389592352029089
2007	2.633331949848729
2008	2.519641304424884
2009	2.5211376157884704
2010	2.3680435697911415
2011	2.5325252705633745
2012	2.5174577200072656
2013	2.7293916388472708