Year	% of energy use
1971	100
1972	100
1973	100
1974	100
1975	100
1976	100
1977	100
1978	100
1979	100
1980	100
1981	100
1982	100
1983	100
1984	100
1985	100
1986	100
1987	100
1988	100
1989	100
1990	100
1991	100
1992	100
1993	100
1994	100
1995	100
1996	100
1997	100
1998	100
1999	100
2000	100
2001	100
2002	99.96740760943679
2003	99.96245436994799
2004	99.95104033263632
2005	99.94039644876366
2006	99.92258631326018
2007	99.91016083263122
2008	99.89158200619906
2009	99.88039998561203
2010	99.41771038014868
2011	99.20049074490304
2012	99.020755696883
2013	98.83961630395726
2014	98.38148616512974