Year	% of energy use
1960	16.716146904005495
1961	17.63580348657212
1962	19.02263030024769
1963	21.14044162201755
1964	21.96150810270334
1965	23.69133985782089
1966	24.519813302689354
1967	24.685404332633833
1968	26.67112704950994
1969	29.326784816325137
1970	29.500019091910712
1971	29.888826194125176
1972	31.50603235402171
1973	34.09480236475143
1974	33.705896460680776
1975	31.50565197463351
1976	34.6990410149752
1977	33.83965617556526
1978	33.90928381096549
1979	31.668407644401707
1980	28.26855099204862
1981	25.37747909300186
1982	22.25606284372585
1983	22.475126088613766
1984	21.091266060693073
1985	20.738009306326624
1986	21.085351698505008
1987	21.372076060834782
1988	22.885127378831086
1989	24.058574618858223
1990	23.50370353280291
1991	23.71115499172075
1992	23.815032059716767
1993	24.97724145219542
1994	23.914184781590375
1995	23.911303781974727
1996	24.099659096496197
1997	24.133431104372747
1998	24.2106617273049
1999	25.77322251369128
2000	26.679741945322576
2001	25.639087352988444
2002	26.556011313704143
2003	27.914397086406886
2004	28.65922694522757
2005	29.358731294816106
2006	29.076069182201902
2007	29.544985625845044
2008	28.307389784362957
2009	26.10110953385134
2010	26.909432235018993
2011	25.67657391679727
2012	24.527138175798278
2013	23.16355441953763
2014	19.644325896656344
2015	20.969042498325923