Year	% of energy use
1965	28.142866564664498
1966	29.73080985296706
1967	32.7514914576146
1968	30.724101724770232
1969	33.32372092051365
1970	34.18597999314334
1971	37.765568200393055
1972	39.72766838072485
1973	40.31059955518243
1974	42.211116122329955
1975	45.27625942696355
1976	44.95293398183658
1977	45.667113263540486
1978	46.270276252344615
1979	48.0993438078606
1980	48.881577830950604
1981	48.81325911470073
1982	47.03133756291836
1983	45.70235477002283
1984	45.73941106663779
1985	44.855917054058516
1986	45.73991160011816
1987	45.3316955956135
1988	46.041076658307986
1989	46.73552831782198
1990	48.97203155787429
1991	47.31799676926979
1992	44.6183660504926
1993	46.70484889710816
1994	46.633040659404934
1995	46.26983086657129
1996	48.57375559218502
1997	48.761402724372616
1998	51.48222863645461
1999	53.254589588624846
2000	53.525021511815595
2001	55.84826994351839
2002	56.257464237768794
2003	60.16618772953189
2004	60.73495783043934
2005	62.360689954960726
2006	62.17671338029385
2007	61.74633199480601
2008	60.341428448149095
2009	55.68995729219453
2010	57.00256941061909
2011	56.7665196485137
2012	54.90329055310469
2013	54.576492132248
2014	55.60738232183047
2015	57.66670547678735