Year	% of total energy use
1960	8.31403322905605
1961	8.017883588647589
1962	7.36191293695044
1963	9.31613770624839
1964	8.21607764654165
1965	7.413305525224116
1966	9.182349899225525
1967	6.764175298083377
1968	6.44006804413946
1969	8.112260074973246
1970	6.922392727152271
1971	7.965241566610364
1972	9.565249587449314
1973	8.128627450067905
1974	8.070955036277654
1975	7.318911174889766
1976	6.106732953905644
1977	8.422098071717528
1978	8.419939952058334
1979	8.719779493458327
1980	5.750613424882966
1981	6.373974458069187
1982	6.8045507372061955
1983	7.506249383193852
1984	12.550818618750412
1985	14.10178679052324
1986	16.63567120880462
1987	17.680980061469622
1988	20.20797975708219
1989	18.492953416926902
1990	17.747611832238245
1991	17.60981394437723
1992	16.734850630212897
1993	17.977760719529464
1994	17.1760956942237
1995	16.11094434147604
1996	17.817894994574033
1997	16.17016640915075
1998	16.292314204050854
1999	14.91444158716897
2000	15.380378167888797
2001	16.197439012338325
2002	14.605359085201176
2003	15.101411128892675
2004	14.462232049196293
2005	12.692517767955996
2006	13.707770003075412
2007	12.930193549705923
2008	14.255353880585428
2009	14.97963590121655
2010	18.37506615333503
2011	17.389135283014813
2012	18.749414342278783
2013	20.812756639995985
2014	21.600495993752585
2015	19.97537665385849