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	34.02968574072346
1972	32.958533227815536
1973	31.822994566878656
1974	31.385685301474595
1975	29.74224930523464
1976	28.801734633099866
1977	27.291765478755003
1978	25.745219175142072
1979	25.464827093424873
1980	25.287272444067163
1981	25.50817845698842
1982	25.029063199599847
1983	24.68477735441671
1984	24.02225632282172
1985	23.67027604832096
1986	23.157309852935263
1987	22.529951781010052
1988	21.766155444679658
1989	21.731788539239616
1990	11.636832995412318
1991	11.782156017531484
1992	12.05682042363837
1993	11.95582899823499
1994	12.046048876304841
1995	11.680406618099058
1996	11.479096453270387
1997	11.422210194801025
1998	11.382127155970146
1999	11.326036608286676
2000	10.786008622305317
2001	10.229843582064829
2002	9.896668403971447
2003	9.013167793926113
2004	8.14781876313018
2005	7.5414578353644455
2006	7.103114021343127
2007	6.540453116184096
2008	6.097308832421547
2009	5.798782381833462
2010	5.311882552974467
2011	4.767883019882232
2012	4.492623734880003
2013	4.2919079731255945
2014	4.247144653444707
2015	3.1460913773944923