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	0.018745967611029847
1974	0.03662120385210299
1975	0.045143065520395764
1976	0.039676406578853254
1977	0.09553675373367555
1978	0.14109365639703397
1979	0.14806418890975537
1980	0.12270309635438972
1981	0.12864183202472007
1982	0.1393273289097047
1983	0.2786064710877217
1984	0.2748415128515759
1985	0.35792982067051915
1986	0.4446387209459904
1987	0.4232184597207947
1988	0.4572766725921124
1989	0.8587536616740556
1990	0.6902250584406876
1991	0.6637840611963012
1992	0.6339243743538351
1993	0.50516173583094
1994	0.46056128881794156
1995	0.6542598624029919
1996	0.6341109158819717
1997	0.5926863208633819
1998	0.666799514681789
1999	0.7289274314430482
2000	0.7193547824281933
2001	0.8029365068629104
2002	0.8488127390121296
2003	0.9774869746493331
2004	1.0334520425063594
2005	1.2028424017313701
2006	1.4292351002775998
2007	1.7227136659332731
2008	2.0046743939481133
2009	2.3965736658718395
2010	2.871754500595104
2011	2.9583519114725
2012	3.4805444331428808
2013	3.469717313074046
2014	3.4607662191291584
2015	3.4690486751156975