Year	% of total energy
1971	1.5534185596223569
1972	1.2220052031004265
1973	1.1665707526056652
1974	0.69141297741923
1975	1.1079140512257528
1976	1.2075959123304865
1977	1.1087786232851904
1978	1.0797068781571875
1979	1.0231405521989125
1980	0.7236462425793588
1981	0.7087245666451938
1982	0.6972355040938545
1983	0.6451821782797226
1984	0.714345879471546
1985	0.7323067554047589
1986	0.6473064304808851
1987	0.5489689610667324
1988	0.4975798996902735
1989	0.4781271525851678
1990	0.30759380915265555
1991	0.2585589323425497
1992	0.22662448756020312
1993	0.20965157452489863
1994	0.41139344130223826
1995	0.43207287003651645
1996	0.44564656162822847
1997	0.36945852825312514
1998	0.3751085401077203
1999	0.36498187422798106
2000	0.30510974591658335
2001	0.3433866150167791
2002	0.42302258173490587
2003	0.5055982927426552
2004	0.474970423087207
2005	0.4347252079791541
2006	0.4634801951997157
2007	0.6652670398549135
2008	1.301845235560751
2009	1.4236742619983551
2010	1.3790455010503326
2011	1.4866164821698082
2012	1.3085456048666508
2013	1.4241310314500135
2014	1.2872954276353137