Year	kg per kg of oil equivalent energy use
1971	3.113008730407021
1972	3.189717016793483
1973	3.2530901174356384
1974	3.0755133453802177
1975	3.0153709406350075
1976	2.9824536156843915
1977	2.7591383922676327
1978	2.6455348236180307
1979	2.7102356491568944
1980	2.6656057964323447
1981	2.550015515546079
1982	2.3348651543709114
1983	2.2826890643636584
1984	2.3113190093444884
1985	2.2439762103930927
1986	2.221976320160822
1987	2.193930744431705
1988	2.301868677439298
1989	2.469941807896506
1990	2.1706923694916718
1991	2.063518391002948
1992	2.032810162837196
1993	2.034511615801567
1994	2.0727232953652375
1995	2.085404994645825
1996	2.1687322947570036
1997	2.2225132237558705
1998	2.182478926724703
1999	2.148403241343957
2000	1.9795170447264763
2001	1.9382612569674864
2002	1.9043669845422426
2003	1.931999127484265
2004	1.9893520775153053
2005	1.964468781481476
2006	1.9323592300857595
2007	2.1141474377163316
2008	2.2503243681839282
2009	2.214235873534174
2010	2.260141509755078
2011	2.275244074003779
2012	2.1095407170519453
2013	2.1434580221681734
2014	2.1159020746448927
2015	2.2745148203495402