Year	% of total energy use
1960	0.06413961275405274
1961	0.06884301923779926
1962	0.05812340594822433
1963	0.08712623562949448
1964	0.08180370012734783
1965	0.0793242141232911
1966	0.09382855557443194
1967	0.14744768918991194
1968	0.10680431926038277
1969	0.06822005420917976
1970	0.09019069103636117
1971	0.029057327252374032
1972	0.0422286138896533
1973	0.07504475515507042
1974	0.13121582330305706
1975	4.2148887425709125
1976	5.783809108668182
1977	6.938987604315107
1978	6.906848960279967
1979	6.106226236759639
1980	7.044037419398045
1981	7.773548933849145
1982	9.910758663946629
1983	15.407094337352708
1984	16.993977539855507
1985	20.500091471382426
1986	22.529674073767076
1987	23.51794301358982
1988	23.84446610954945
1989	22.58341883818372
1990	23.3009151038854
1991	22.38352730326742
1992	22.460524542133285
1993	22.188876830849495
1994	20.285922805536757
1995	20.28564035218056
1996	20.17245711595631
1997	22.067398392952974
1998	21.156380702515655
1999	22.361276917588658
2000	21.739083344012748
2001	21.018788720251262
2002	22.333604194297756
2003	21.453005432336226
2004	21.343044570653504
2005	21.54986472598122
2006	21.312115469553685
2007	22.39314979094136
2008	20.623557694200507
2009	22.382430762995742
2010	21.242316012202043
2011	23.24318162871486
2012	20.747407459764446
2013	21.42550250609091
2014	18.589631022201537
2015	15.110327401377042