Year	% of total fuel combustion
1960	37.81706379707917
1961	38.267716535433074
1962	37.750385208012325
1963	40.587823652904135
1964	40.74324324324324
1965	41.45885286783042
1966	42.0353982300885
1967	42.04236827810973
1968	40.082009226037925
1969	39.24632352941176
1970	38.304093567251456
1971	37.49456285341453
1972	38.55626326963906
1973	40.75342465753425
1974	44.68929043631556
1975	40.80508474576271
1976	40.25256511444357
1977	37.810383747178335
1978	36.373707533234864
1979	36.71413685307399
1980	36.83437385236871
1981	36.292223095051064
1982	34.33388157894737
1983	32.622950819672134
1984	34.41117764471057
1985	33.20711851571374
1986	29.821608885897
1987	28.690605730866885
1988	27.371078254597908
1989	26.06127722406792
1990	22.723962126729788
1991	19.152215799614645
1992	15.77123050259965
1993	15.26867627785059
1994	17.37776393646839
1995	17.961783439490446
1996	18.912237330037083
1997	16.886543535620053
1998	16.72727272727273
1999	16.447191615157216
2000	20.614998431126452
2001	18.88686131386861
2002	16.553846153846152
2003	18.88191671420422
2004	19.30860033726813
2005	17.7732676138011
2006	17.207334273624824
2007	16.62503469331113
2008	17.30878186968839
2009	14.269694421082141
2010	15.91271953166578
2011	16.137054434926775
2012	16.346696781479388
2013	16.723646723646723
2014	16.086094590767487