Year	% of total energy use
1960	0.8061091873266525
1961	1.0026897227851863
1962	0.8154736857379167
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	1.3420477456794808
1972	1.420115683866055
1973	1.1180967551088041
1974	1.3441198110985626
1975	2.1057905690084326
1976	2.6716415757511647
1977	2.490695858174808
1978	2.7138794058966274
1979	3.124474248790473
1980	3.2947501115683364
1981	3.611850825617266
1982	3.85967811881833
1983	3.013424031303625
1984	3.6405514519435767
1985	3.2386761629272747
1986	3.2286903342710853
1987	4.2268979615950215
1988	6.136493825389296
1989	3.9867143870389006
1990	3.704351706669746
1991	3.7219581187344595
1992	4.117745588759616
1993	4.812865000235375
1994	4.5022165764445825
1995	4.6996537081989
1996	4.86538277941767
1997	4.767416477138413
1998	5.028147605170353
1999	4.464698751579748
2000	3.8531375922552713
2001	3.6864425300182955
2002	4.4898633335877
2003	4.534093079636488
2004	5.380896069539475
2005	4.779884576129985
2006	4.690947963359066
2007	3.8340178963328446
2008	3.8639078310947026
2009	4.385029541695553
2010	5.327704599439173
2011	5.381131131609559
2012	5.727098586540859
2013	6.115137796576509
2014	4.950173582462818
2015	6.654300586536417