Year	% of energy use
1960	12.335653942186566
1961	12.586700771082118
1962	17.941880543194703
1963	18.02619834503623
1964	19.24357063385389
1965	18.820090522768627
1966	19.350595763955873
1967	16.25670021039854
1968	18.0882742089527
1969	19.435914726701185
1970	23.184991572491263
1971	45.50311125415329
1972	45.42014220027121
1973	48.46386596622874
1974	50.90619843738845
1975	51.282851143381436
1976	53.16926960791246
1977	55.696395104556146
1978	54.78745378876847
1979	53.67476607161977
1980	54.97902671595098
1981	53.30455583238043
1982	52.99065435876568
1983	53.74972908597238
1984	52.82930972156683
1985	52.93038349181668
1986	52.22376349113656
1987	52.76797758390185
1988	53.14771055453194
1989	53.05497136821076
1990	-15.250465667037881
1991	-10.68085953844587
1992	-13.399578117782477
1993	-14.162580488595363
1994	-19.061909403604435
1995	-19.087895268198956
1996	-20.649355982716212
1997	-21.36110513817104
1998	-24.296243934329752
1999	-26.166415906727064
2000	-28.791810315729908
2001	-32.32159429749293
2002	-35.64462655165628
2003	-38.937531336588144
2004	-43.27549475207306
2005	-46.51130066948311
2006	-46.00679846780796
2007	-47.30687777224751
2008	-48.47876189181354
2009	-51.801258135192974
2010	-50.83280814435486
2011	-47.831469648434634
2012	-47.33112531005951
2013	-52.80926221699427
2014	-53.259184922822605
2015	75.2078800411834