Year	% of total energy use
1960	0.8061091873266525
1961	1.0026897227851863
1962	0.8154736857379168
1963	1.4806813793121174
1964	1.105815086661768
1965	1.409250236588663
1966	1.373220706346643
1967	1.3493500040400082
1968	1.7038788894443258
1969	1.7495392460005037
1970	1.5558481892071114
1971	1.4471712334104148
1972	1.4884164218419067
1973	1.6097059245083098
1974	1.7487512553095175
1975	1.9381908553624394
1976	2.1166986440661137
1977	2.0465296843872953
1978	2.2167471046721103
1979	2.2916334614920477
1980	2.370560470997178
1981	2.5230754823667874
1982	2.479507395227323
1983	2.5971726650590368
1984	2.920442388432358
1985	3.047140857024631
1986	3.3282716150788847
1987	3.403100499210976
1988	3.686229012514669
1989	3.614133453303532
1990	2.2687842205261313
1991	2.257286115449936
1992	2.278348658464131
1993	2.2475471326407312
1994	2.2682883270113448
1995	2.3233379407138783
1996	2.3100036535870885
1997	2.3461515626567064
1998	2.3438969733579635
1999	2.286486990401163
2000	2.297900284860765
2001	2.285617628262644
2002	2.2539506709902493
2003	2.2968369831002233
2004	2.322379493270881
2005	2.344544955557237
2006	2.4065020087075184
2007	2.2855049221058676
2008	2.2035300309265735
2009	2.194966592515354
2010	2.320033612900463
2011	2.5476801463110013
2012	2.443828577450389
2013	2.6590376128419173
2014	2.4185630454171756
2015	4.830946728340866