Year	% of total energy use
1960	2.727827716374737
1961	2.800560097075915
1962	2.7646641274614474
1963	2.773203192497276
1964	2.778783658519509
1965	2.9818181048177133
1966	3.0748113304328926
1967	3.0543203511070476
1968	3.0518646445875888
1969	3.0664227830015465
1970	2.9861534453868135
1971	2.706011972551987
1972	2.9240866566279626
1973	3.075137287761435
1974	3.5862107630531197
1975	4.147384240414062
1976	4.162020498957886
1977	4.513245375243855
1978	4.878370631995015
1979	4.968432114143057
1980	5.284379765158144
1981	5.952852569599956
1982	6.322326688299292
1983	6.88539362803185
1984	7.507469472609651
1985	8.26970984480702
1986	8.669028770395673
1987	8.828670599129993
1988	9.084804666691177
1989	9.153488474807506
1990	8.048778793805079
1991	8.343299087826907
1992	8.391454054283866
1993	8.596767018985267
1994	8.718204025024447
1995	8.86255769130338
1996	8.941589679122787
1997	8.814975086737931
1998	8.939041357937496
1999	9.041371504708403
2000	9.051321315314693
2001	9.055738192033322
2002	9.009325182272747
2003	8.697014644112514
2004	8.70272783553262
2005	8.628643215869742
2006	8.563774014029619
2007	8.265278234672017
2008	8.326465255519421
2009	8.415198435379926
2010	8.258011322982792
2011	7.938524972471915
2012	7.745533184122677
2013	7.913614123378819
2014	8.134738484269688
2015	13.354082784059226