Year	% of total fuel combustion
1960	24.162058458413274
1961	23.92611214340365
1962	26.110399676484462
1963	29.27101611102249
1964	25.646207208565823
1965	25.95943648287588
1966	25.280605184661276
1967	25.618462076400828
1968	25.804007408654655
1969	24.861147844485583
1970	24.122193595877807
1971	26.367524396871534
1972	28.87824897400821
1973	29.85723022417175
1974	26.958389026447836
1975	27.31764984040667
1976	25.32025663735931
1977	25.609538667260978
1978	27.237354085603116
1979	25.252951096121418
1980	24.207796774051772
1981	26.06441785617768
1982	25.068679555315924
1983	26.341554758974905
1984	27.36102271783945
1985	28.188797270400904
1986	30.055924808947974
1987	29.13085004775549
1988	26.819613135402616
1989	25.27208156718983
1990	24.775687409551374
1991	25.71922526270294
1992	25.82683741648107
1993	26.32768030045185
1994	25.119938019607257
1995	24.503696803865633
1996	25.87852313513814
1997	24.95440556252137
1998	24.445458939792687
1999	25.231247783022724
2000	23.500205733095598
2001	24.60878069984786
2002	23.24779249448124
2003	24.180361265788406
2004	25.157880471608625
2005	24.391231574968952
2006	23.69434516388219
2007	22.00589468911183
2008	24.039067422810337
2009	25.752077022284876
2010	24.791225593977888
2011	22.576904493477212
2012	24.27654796278473
2013	24.724876233721186
2014	23.400308036964436