Year	% of energy use
1960	62.95183912258039
1961	65.72257496427014
1962	66.4259371852047
1963	67.55918117389508
1964	68.55390507690248
1965	74.34455947353273
1966	73.23580237341385
1967	73.47701098450388
1968	68.81789597572104
1969	71.96045160080389
1970	76.33035853487318
1971	78.81268866885378
1972	79.42222016152375
1973	83.7813623184881
1974	81.61370531069406
1975	75.03205202462583
1976	79.38253806176493
1977	81.5872047698843
1978	84.50800890092346
1979	82.84813557537959
1980	77.00735342330026
1981	69.89145417996411
1982	63.08174557327213
1983	60.88666991976742
1984	56.20940442426996
1985	67.02034623429205
1986	70.25748142831833
1987	67.41831688850333
1988	68.56459302920996
1989	59.66287905645095
1990	65.01930006392995
1991	67.11338610425356
1992	68.79476202478092
1993	65.70391658665888
1994	66.29656866852682
1995	61.50827209462888
1996	68.83993320024685
1997	76.15101187517232
1998	80.61126416875643
1999	81.51841800568768
2000	84.3605375610743
2001	87.63821756206073
2002	89.2733634919119
2003	86.94247192281345
2004	87.0470190525814
2005	88.70219823143329
2006	88.76827720137058
2007	90.67819743790511
2008	89.52857173770154
2009	89.8617931557646
2010	87.24518693092384
2011	87.18399147432761
2012	90.42999776114273
2013	82.71123563513785
2014	84.25580304635804
2015	85.66713691559691