Year	% of total energy
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0.27842339371977787
1971	0.2064066666468053
1972	0.22162287000101252
1973	0.20462576306718672
1974	0.9965555888761395
1975	0.9502864063731634
1976	0.8260836777987726
1977	0.7542960746664713
1978	0.6492565233090518
1979	0.6551034670628648
1980	0.7004234363212389
1981	0.7713922282954516
1982	0.7531153079625095
1983	0.7734883533218962
1984	0.7931406981302038
1985	0.6798820470949161
1986	0.8286689948757626
1987	0.7449916208065741
1988	0.7598065105675467
1989	0.6902123797523005
1990	0.4948438376199901
1991	0.5746397384201992
1992	0.6834376343752904
1993	0.6441723643810525
1994	0.7844740775717624
1995	0.7192014056005682
1996	0.6910156726444628
1997	0.7589709920304116
1998	0.7738040181255121
1999	0.8239357936171756
2000	0.9051178687535111
2001	0.942791222126634
2002	1.4365537060872025
2003	2.1183842313451993
2004	1.6101177116629042
2005	2.4433041018926445
2006	2.8863805826607014
2007	3.852768626619264
2008	4.949828202644703
2009	5.521349755268623
2010	5.403959234025859
2011	4.097784657691932
2012	5.587217102361764
2013	5.915371044613208
2014	5.657802821562774
2015	6.115326619966066