Year	% of total energy use
1960	12.062295955434351
1961	11.45254344741468
1962	10.89471398845348
1963	10.150130039788117
1964	10.418460344801769
1965	10.046359914793944
1966	10.700228109216718
1967	10.188471170812853
1968	9.813260997218702
1969	10.222014205388321
1970	10.04328603472367
1971	10.670940083899549
1972	11.475892904263784
1973	13.06035247523599
1974	13.705087858708726
1975	12.581980701782495
1976	13.459828113678544
1977	14.699077303733585
1978	15.876887874028178
1979	16.171147666860133
1980	16.672452915381264
1981	18.154385938005287
1982	18.43107348054687
1983	20.290384043495475
1984	20.70796405398314
1985	21.998165389867193
1986	23.410537042669187
1987	23.65510054594368
1988	22.88449569312331
1989	21.35515028918624
1990	19.674876753156774
1991	21.19362784265759
1992	20.152190031653863
1993	21.20605130212777
1994	21.915530680576598
1995	20.806662252309984
1996	20.32661272249292
1997	18.990979010163397
1998	17.482059096700112
1999	17.520151098377852
2000	17.189100712955966
2001	17.388974070751498
2002	17.689342079171347
2003	16.79457254502699
2004	17.951546727767557
2005	18.31901904312933
2006	18.812429106295603
2007	18.73280272510192
2008	19.18589098705962
2009	18.899583849601736
2010	18.561148989550258
2011	18.709067554693203
2012	19.347644426594776
2013	19.91241795874621
2014	19.691110602519664
2015	19.770846389417976