Year	% of energy use
1960	12.335653942186566
1961	12.586700771082118
1962	17.941880543194703
1963	18.02619834503623
1964	19.24357063385389
1965	18.820090522768627
1966	19.350595763955873
1967	16.25670021039854
1968	18.0882742089527
1969	19.435914726701185
1970	23.184991572491263
1971	-48.38879855669276
1972	-48.14827980347292
1973	-52.37264776942919
1974	-48.563267270359745
1975	-41.93844622435448
1976	-45.946504017903344
1977	-43.07807132449741
1978	-40.17308184409668
1979	-37.60722353366644
1980	-27.79320158171977
1981	-19.43220576285434
1982	-21.740197513126315
1983	-23.624417284035886
1984	-25.46778758680653
1985	-25.56728316183423
1986	-23.585161823640895
1987	-23.529232120595214
1988	-24.67557916101359
1989	-26.778042070401092
1990	-22.31586191414825
1991	-19.54927046935228
1992	-20.281605976676982
1993	-19.320835347580115
1994	-20.69807322515272
1995	-20.223410942843724
1996	-20.7318956160402
1997	-21.39888940049895
1998	-23.196388959067274
1999	-22.308299828108503
2000	-23.424919096017994
2001	-23.498949526337803
2002	-22.56888186418451
2003	-22.796154972059117
2004	-22.12760710720188
2005	-21.858430714181395
2006	-20.69383293789812
2007	-19.22930786747041
2008	-18.150064802092448
2009	-16.001393251432955
2010	-14.692633705245456
2011	-12.932638134924217
2012	-10.700146334821145
2013	-9.800515395279055
2014	-8.105703541316545
2015	28.00817540414526