Year	% of energy use
1971	1.656192946109145
1972	2.1766500411602396
1973	2.9868539693720666
1974	2.7715177211909148
1975	2.4812169787978693
1976	1.9595480725006604
1977	2.2136767429510216
1978	2.1454054889459497
1979	3.126472339609012
1980	3.4848460602080267
1981	3.0160590988630025
1982	3.465645842145619
1983	4.475277245465939
1984	4.791268876329494
1985	3.5668146060635335
1986	4.524513055996817
1987	4.249346328967072
1988	4.434043294105295
1989	3.431404268229995
1990	4.981320286438389
1991	5.966662065446092
1992	6.33781030882571
1993	6.772948182191417
1994	7.953062402525825
1995	8.540754640179205
1996	8.736276910756843
1997	9.829249252288097
1998	10.128939121552346
1999	12.659638019277649
2000	11.95500828531837
2001	12.378362571214016
2002	10.036120695203806
2003	10.485809253889164
2004	9.770678759036132
2005	10.72711085218177
2006	8.936978636363682
2007	8.862617963739131
2008	10.06937329647098
2009	11.437417938937653
2010	13.067170169365097
2011	13.505459456124694
2012	15.765661873010336
2013	14.594761292296116
2014	16.67706471383556