Year	% of energy use
1971	-64.26397790206221
1972	-53.069725646363565
1973	-50.802376230378655
1974	-38.60788720073057
1975	-25.743043269098163
1976	-21.693001073948224
1977	-20.560777705100445
1978	-19.703100818985174
1979	-24.284868900838035
1980	-25.64638403323926
1981	-30.853433753519866
1982	-33.671219948632356
1983	-34.63747157391684
1984	-36.38842132635444
1985	-34.05401774075823
1986	-32.26661118334776
1987	-30.76896033758601
1988	-31.652837400869917
1989	-30.556562405026348
1990	-34.738208594524586
1991	-36.81356788567965
1992	-34.78938210695226
1993	-37.47087991048535
1994	-34.881810779928536
1995	-39.31007894347829
1996	-43.32486345535929
1997	-44.48169984056221
1998	-42.340442379328124
1999	-39.23610303427122
2000	-41.82327623840477
2001	-41.86468790251002
2002	-40.92332406719643
2003	-40.634591748245825
2004	-43.7391463915557
2005	-43.046540722981106
2006	-41.12687059992378
2007	-34.93519469967568
2008	-30.693094992456057
2009	-32.10139811064303
2010	-27.653348531125626
2011	-28.219705963744712
2012	-24.108603324160743
2013	-21.886126236358137
2014	-8.087128885434357
2015	6.611815932493566