Year	% of total energy use
1971	2.1170660551993157
1972	2.2549752959505533
1973	1.7809096836043676
1974	1.8839043643641777
1975	1.8163894771241818
1976	1.8725383795033093
1977	1.9367451657763173
1978	2.1303475009150854
1979	1.877988098863694
1980	1.8418489062790184
1981	1.7264186773052435
1982	1.5373660599285008
1983	1.430138802384054
1984	1.305073809686347
1985	1.1706418759531025
1986	1.2288657818302815
1987	1.342611500857497
1988	1.2368136050939484
1989	1.1944093589771743
1990	0.9401861376799647
1991	0.8802821682382379
1992	0.877933748419733
1993	0.8219025181882078
1994	0.716456987243281
1995	0.6834800094537052
1996	0.7506154310421423
1997	0.6917616517122588
1998	0.7075959203306538
1999	0.6495421513458053
2000	0.5796347951154366
2001	0.6148631488320262
2002	0.602303035371949
2003	0.7049437036154879
2004	0.6688233659902779
2005	0.7930120976984649
2006	0.8087800877993079
2007	0.7891187856552141
2008	0.4952450720649931
2009	0.5229416779751938
2010	0.6344171074009588
2011	0.6615711746566144
2012	0.734444187164884
2013	0.9461394694435854
2014	0.8603160016805881