Year	% of energy use
1971	14.612364977734394
1972	15.466373360840258
1973	16.21764464678389
1974	13.75115553558784
1975	15.22263306082296
1976	16.209813313392186
1977	22.19771888108277
1978	25.534821573647697
1979	23.946996045177247
1980	22.992681297037077
1981	21.952918802640582
1982	22.224666097092065
1983	20.016297779772792
1984	21.497654419987654
1985	10.941526632190973
1986	-16.952878971564896
1987	-33.635323123184804
1988	-32.11966921109077
1989	-36.14517850188895
1990	-48.98478297234195
1991	-53.71145450481733
1992	-43.08259057589105
1993	-46.97823512286281
1994	-50.093424004404696
1995	-53.50018009994911
1996	-59.0432307361037
1997	-60.51164987441583
1998	-59.22519764809952
1999	-63.85877656361622
2000	-77.55350678257186
2001	-57.08348885511562
2002	-61.942844026049634
2003	-67.00574585401307
2004	-65.56457789108153
2005	-66.23010315735505
2006	-70.83477222110433
2007	-68.8639945212632
2008	-66.46353791069885
2009	-59.23691151980476
2010	-48.09479982070858
2011	-50.85842076830658
2012	-50.745794045774836
2013	-50.809061947189235
2014	-36.93956313474093