Year	% of total energy
1971	13.240411532622776
1972	10.454242872000776
1973	8.31214980315946
1974	9.37778446751917
1975	9.036429638164703
1976	10.073591060353552
1977	9.452537982705877
1978	9.848912004407069
1979	8.30255342163822
1980	9.372982457834329
1981	9.195929476413186
1982	10.289497944328662
1983	11.102639978936525
1984	12.93869651016674
1985	13.879729768911824
1986	13.839548644243457
1987	13.634158229575217
1988	13.708427183111183
1989	12.98326776829834
1990	5.1117341916661605
1991	5.126302638531961
1992	5.117112753680231
1993	5.320988248402701
1994	5.395617672105189
1995	5.270714270099776
1996	5.251795181183438
1997	5.3959979884296185
1998	5.0003228634851755
1999	5.070717581772866
2000	6.4504314382428625
2001	6.089914122361909
2002	7.711552284430172
2003	7.6258119401908715
2004	7.885275927219635
2005	8.060978430726783
2006	7.296762603068825
2007	7.129735318029891
2008	8.106204774192266
2009	9.13235884216051
2010	8.930632237082735
2011	8.891856326136809
2012	10.986517535501218
2013	10.772915029164052
2014	11.13282011221957