Year	% of total energy
1960	54.994828279902826
1961	54.838206026885075
1962	50.13486057208687
1963	46.89303911469657
1964	44.91927730462725
1965	42.5090200559124
1966	39.177557455789305
1967	38.02604564636631
1968	36.11291959246811
1969	34.08936710412753
1970	32.79012777077308
1971	42.03181558367933
1972	41.74336853784235
1973	39.96513642246542
1974	38.95122597475985
1975	38.17352909907223
1976	37.01590956189782
1977	35.8856331346547
1978	35.0672936789837
1979	33.74851667918632
1980	32.35372187616441
1981	30.86541669146905
1982	29.750032058953554
1983	29.861194209842033
1984	29.387987836946895
1985	28.851416910585908
1986	28.261828280095656
1987	27.314997909976675
1988	26.728407710661376
1989	26.253247100357463
1990	23.404178695583145
1991	22.748606235707392
1992	22.448856982239153
1993	21.91601805368809
1994	21.323590133708564
1995	20.899727163727075
1996	20.497916466909285
1997	20.080853911377417
1998	19.8124335482804
1999	19.297219157272618
2000	19.096095191190415
2001	18.858624338976078
2002	18.537414560487054
2003	18.225951318147807
2004	17.46208638175633
2005	17.038081942428914
2006	16.542827088985476
2007	16.146579232305573
2008	15.671154331959752
2009	15.375705049881821
2010	15.066124212004771
2011	15.015335762068723
2012	14.624693373362788
2013	14.852379865397179
2014	14.766919311621905
2015	2.933450289015929