Year	% of energy use
1960	25.019422371219886
1961	18.36862015114487
1962	10.515045979222634
1963	11.421954339718248
1964	10.006309793279742
1965	11.536018438818054
1966	8.388174708316095
1967	8.259477886800441
1968	7.0201854748690105
1969	2.004650070444979
1970	-4.822199863146583
1971	-10.24871865292163
1972	-15.94964271133966
1973	-24.39625384233592
1974	-18.65129600484823
1975	-13.018307809906998
1976	-6.486679352663366
1977	-7.710029906558842
1978	-5.437346401048085
1979	-10.435063763229133
1980	-7.934874521558561
1981	-6.8749072534919105
1982	-12.345262194915959
1983	-15.4200029612334
1984	-21.21227816204151
1985	-24.998445526684886
1986	-22.09220066290742
1987	-24.55438908338399
1988	-29.118201482969702
1989	-26.14821544883291
1990	-30.835755236887763
1991	-36.56028250061904
1992	-37.54038478251183
1993	-42.892386217409076
1994	-47.835757214191375
1995	-50.50588106804299
1996	-51.2684199598067
1997	-52.383901118203404
1998	-53.536082803911675
1999	-48.7356760905854
2000	-47.804356415708845
2001	-51.668195278346104
2002	-54.12409412695918
2003	-47.046452799054585
2004	-48.23775636839017
2005	-48.953644870421314
2006	-53.80949229648226
2007	-53.29171757634333
2008	-50.42825604153691
2009	-50.197715125769626
2010	-51.37487379844099
2011	-52.96207891631265
2012	-59.114160400190755
2013	-64.44374805110212
2014	-67.92722174303826
2015	-72.5281697658652