Year	kg per kg of oil equivalent energy use
1971	1.403411489666733
1972	1.3088429091383127
1973	1.314623192484041
1974	1.3075934793301502
1975	1.3688975888245498
1976	1.3746764064903894
1977	1.4138313817922052
1978	1.417680679665888
1979	1.4275072584681945
1980	1.4763306368635438
1981	1.5152572556366866
1982	1.5110142110078284
1983	1.5781083850351274
1984	1.5610432171220887
1985	1.632861452234378
1986	1.6841591332130939
1987	1.726414776921946
1988	1.769558021417468
1989	1.841257771776284
1990	1.7172298194117905
1991	1.768188249591426
1992	1.779242454525395
1993	1.801835213456475
1994	1.8294401177968862
1995	1.870702646360562
1996	1.899034750613383
1997	1.933397159359462
1998	1.9274759520937372
1999	1.9686133901627927
2000	1.990790950988092
2001	1.9933335450001495
2002	2.0077171912348275
2003	2.0118166287679404
2004	2.052585954862421
2005	2.0668192941553363
2006	2.1001243284771656
2007	2.1889258983786273
2008	2.2229405938412814
2009	2.234568328679438
2010	2.2615751731710128
2011	2.296723863733534
2012	2.3711457723761638
2013	2.3841043568090066
2014	2.446459862897122