Year	kg per kg of oil equivalent energy use
1971	0.9479640862538018
1972	1.1210343675352195
1973	1.300922584571519
1974	1.537550090017375
1975	1.2173731190278707
1976	1.2915886785492587
1977	1.1759891875238841
1978	1.13145247444433
1979	1.4530559542190868
1980	1.4030541271864547
1981	1.3141710943474871
1982	1.302289804449795
1983	1.1736227027620874
1984	1.2994042123172882
1985	1.3004332343330651
1986	1.2261331150567298
1987	1.0176447465976826
1988	1.167668512045264
1989	0.8794086962077229
1990	0.9723912067856605
1991	1.0362008455236753
1992	1.1175761660869048
1993	1.1201693767153884
1994	1.1048236489517778
1995	1.0923932383259858
1996	1.1106903945620055
1997	1.0592486334267315
1998	1.0084362344892568
1999	0.9722158048705689
2000	0.9510190160103056
2001	0.994898643692471
2002	0.9808738444281018
2003	0.9531035132057322
2004	0.968156953407103
2005	1.0312939526327816
2006	0.9932988022357103
2007	0.9549272730900457
2008	0.900890503179282
2009	0.8095830515841537
2010	0.8716074964683431
2011	0.901052746889454
2012	0.8652299073730398
2013	0.9045954256113661
2014	0.9314337465027399