Year	% of total energy use
1960	1.660477074703614
1961	1.8449266179570003
1962	1.8783279243556814
1963	2.3355006551983184
1964	1.8413041875712781
1965	1.6828051736377623
1966	3.1565565485712543
1967	2.7051512135187825
1968	2.0641115344478265
1969	2.7766496225764414
1970	2.9539947913911226
1971	2.6245004235273863
1972	2.282432451858612
1973	1.6186336330323248
1974	1.792649269389867
1975	1.4755294480477652
1976	1.2688270977509752
1977	1.2083393338972035
1978	1.786376936322678
1979	2.0100136268222215
1980	1.9545001861190372
1981	2.000643205814253
1982	2.0349653137708317
1983	1.278083672182589
1984	1.5049262654487867
1985	1.3744057872835986
1986	1.6675956394960445
1987	1.334676384253937
1988	1.0657964179204504
1989	1.0187242231007894
1990	0.8589186144191056
1991	1.319659913766164
1992	1.03827392715567
1993	1.1077511716605604
1994	1.1884202409365852
1995	1.4928998203752086
1996	1.7320543075437802
1997	1.569568940226105
1998	1.4590933910137236
1999	1.694183738411864
2000	1.4380196018130218
2001	1.1285467533434932
2002	1.2989270431047473
2003	1.816244832732493
2004	1.867074828154831
2005	1.9518503609980722
2006	2.3289910809923318
2007	1.7291662888174686
2008	2.076675207650126
2009	2.8216396478240178
2010	3.7682983465711417
2011	3.1154498461775053
2012	3.6953943772812146
2013	5.637234721771404
2014	5.417648103106144
2015	6.202481177316421