Year	% of total energy
1960	3.518888229452025
1961	3.189001479587411
1962	2.957373233724129
1963	2.6920929761699477
1964	2.350151251958997
1965	2.2242437884896673
1966	1.969877844059597
1967	1.7587541519429484
1968	1.5428667933327962
1969	1.3620860605833118
1970	1.126380883921511
1971	25.08935204059243
1972	24.307884978792334
1973	23.170458041344787
1974	23.201342712452664
1975	22.870521519901786
1976	22.202138852493295
1977	21.180140861138483
1978	20.31030515426476
1979	19.877353197294575
1980	20.087540545771926
1981	20.544992429195144
1982	20.652229265184697
1983	20.1429142811215
1984	19.266121879293525
1985	19.145058108502514
1986	18.717898837585583
1987	18.246462161849774
1988	17.49871312846189
1989	17.25948357244304
1990	15.905547625222967
1991	16.008821278143124
1992	15.566120253813024
1993	14.891086596006406
1994	14.220581715639579
1995	13.524702724659075
1996	13.106684117944077
1997	12.952074403793858
1998	12.944803366439116
1999	12.586029165979527
2000	12.043912216261699
2001	11.417893345836802
2002	10.893824149338098
2003	9.887239205165836
2004	8.774066732912383
2005	8.107007538124265
2006	7.623688130453669
2007	6.8862349792776305
2008	6.419972401262378
2009	6.007544549273634
2010	5.344469549038938
2011	4.970921264612867
2012	4.7860988591317275
2013	4.528974778044578
2014	4.232685159520738
2015	1.4720370204871096