Year	% of total energy use
1960	6.223619510640175
1961	6.39675944191993
1962	5.5788663262086144
1963	5.390956502369685
1964	4.796330478168494
1965	4.858976077830606
1966	4.736063431349761
1967	3.4919683413682976
1968	3.357440475482519
1969	2.9899224963487847
1970	2.9951932554280134
1971	3.4860021343896985
1972	3.426093242081506
1973	2.6543997780556947
1974	3.8275588451155187
1975	4.52595141780234
1976	5.006437509627382
1977	4.477300547329774
1978	6.605494381211457
1979	7.3891090860840185
1980	8.675927153550223
1981	9.255478255596755
1982	10.344653208410975
1983	11.364613668173796
1984	11.6829700986475
1985	13.77770039747252
1986	14.170291996815228
1987	15.222346459445202
1988	13.95701986487431
1989	13.75234057435585
1990	13.88412249092245
1991	14.543873550687461
1992	14.56544453483298
1993	16.116417458321187
1994	15.931826947850086
1995	16.939963245415065
1996	17.14409451051015
1997	17.941619890018966
1998	18.984019671365022
1999	17.779357905009494
2000	17.736449367259958
2001	17.862720284707027
2002	16.604542979576753
2003	14.058007669544612
2004	15.743590643827307
2005	16.684405224887907
2006	16.835696388027646
2007	14.771849292928732
2008	15.094273475798623
2009	17.05702974815535
2010	16.663718240565313
2011	7.522000903538151
2012	2.649811404353303
2013	2.431153936003861
2014	2.2218936260236815
2015	3.0920207392351573