Year	% of energy use
1960	88.70139134289663
1961	90.00827897520755
1962	91.38925579668246
1963	92.29122377104086
1964	93.44053647287944
1965	94.15830462944345
1966	94.97353152636451
1967	96.36286089207815
1968	97.89166861287268
1969	98.96787333779618
1970	98.0703340521871
1971	98.22093287920521
1972	97.74592426907395
1973	97.75604391426694
1974	97.45867639859614
1975	96.98730915427632
1976	96.86204882366172
1977	95.31775925022576
1978	95.58819704840191
1979	95.27438064686031
1980	95.02304229828478
1981	90.97683601008416
1982	85.28699067271464
1983	81.25831816834015
1984	79.38205476076469
1985	74.203271810946
1986	66.76010481158008
1987	58.354363282844254
1988	55.531930712426316
1989	45.60560683259679
1990	41.93396516338258
1991	38.09630226789961
1992	29.871003856545435
1993	26.56673939292178
1994	22.87290656638118
1995	19.610423863587627
1996	19.50538867509145
1997	0.46478743249713944
1998	-1.8920438168563727
1999	-24.047899593009625
2000	-48.844189589948634
2001	-41.31370049039239
2002	-50.419351937860014
2003	-41.72095916002883
2004	-60.071115668717525
2005	-65.69405592851673
2006	-45.8611627994167
2007	-36.99421994534331
2008	-38.71495566383637
2009	-30.459883478760553
2010	-19.8620224238206
2011	-14.541945799140214
2012	-8.653717943533918
2013	4.908089604394314
2014	0.9443538046338955
2015	1.774998670992041