Year	% of total energy
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	1.1407943089756298
1983	1.2039316992381799
1984	1.213660500561104
1985	1.254071010749509
1986	1.2631074227740653
1987	1.3052110354206223
1988	1.3039403692850307
1989	1.3282976575908598
1990	0.7591407368817286
1991	0.7519437553312358
1992	0.7126394993413444
1993	0.6680331161060444
1994	0.635657697710801
1995	0.6398433227239804
1996	0.628524481426722
1997	0.6383038743941946
1998	0.5842627835796161
1999	0.6114285252762548
2000	0.6347881743579445
2001	0.584580393868958
2002	0.6090488273235185
2003	0.6223563243033567
2004	0.5904250085613524
2005	0.6376007016864165
2006	0.6567875770140094
2007	0.6931186319582928
2008	0.6744228316165195
2009	0.6513694271576072
2010	0.8833234742713701
2011	0.9263319033147625
2012	0.9291038892752956
2013	0.9899521526428142
2014	1.1028797080616999
2015	1.1596118113714307