Year	% of energy use
1960	41.882660859967395
1961	45.39439445669603
1962	49.96820407972065
1963	57.10391911145805
1964	61.07390029338355
1965	64.24561607799521
1966	66.81865705838906
1967	74.08768084208518
1968	77.12683397332383
1969	81.30983696191429
1970	84.66319914965882
1971	86.62349668099803
1972	88.59214426933897
1973	90.78962873584452
1974	90.48961690522636
1975	90.19156931502054
1976	89.83222625355354
1977	90.31895232381213
1978	89.13971261324842
1979	88.83336952928457
1980	87.43438088518903
1981	86.78777225997246
1982	84.60848708686575
1983	83.61510557924908
1984	83.62831557266378
1985	81.52426946803017
1986	81.23058244240312
1987	80.72037556033715
1988	82.4663907249315
1989	82.90550970528263
1990	82.99873860004226
1991	82.26399861698079
1992	82.39916529543562
1993	80.93673282279295
1994	81.3272733954984
1995	80.19512518456395
1996	80.00005875888856
1997	79.36665258437259
1998	78.42828783279788
1999	79.674112614524
2000	79.8078641502515
2001	79.72095590850137
2002	81.23226885143949
2003	83.67531010576721
2004	82.07032778526965
2005	80.92420742742779
2006	80.71502475897343
2007	82.64541564545547
2008	82.34586692738463
2009	80.36108289264385
2010	80.14407830924529
2011	88.93691414718518
2012	93.82704712482813
2013	93.91862662766074
2014	93.98125951657957
2015	93.01912813954318