Year	% of total fuel combustion
1960	20.548909218859958
1961	22.859164897381458
1962	21.43306096794469
1963	19.486899563318776
1964	19.587133941430633
1965	18.288590604026847
1966	18.38345864661654
1967	18.521229868228403
1968	16.60206718346253
1969	15.378244064053009
1970	15.248756218905472
1971	15.863453815261044
1972	15.324615737554485
1973	15.049050302650805
1974	15.908576601040961
1975	17.093049581163687
1976	15.122048025401865
1977	15.336932613477305
1978	14.243866715488835
1979	15.489833641404807
1980	15.186873290793072
1981	18.53722820118603
1982	19.582482414340824
1983	20.732566330124442
1984	20.687300864815658
1985	19.68096125958152
1986	20.809248554913296
1987	20.701552616446232
1988	21.259230470268168
1989	22.45096135171878
1990	21.757710888145674
1991	20.89825847846013
1992	21.915427688743
1993	20.949510173323286
1994	19.412258606213268
1995	20.39497307001795
1996	17.822100691651922
1997	19.43474646716542
1998	20.862676056338028
1999	21.710408855561507
2000	21.55820348304308
2001	19.666170880846142
2002	19.21425163034834
2003	17.26173741917346
2004	18.824582338902147
2005	23.083941605839417
2006	19.33634992458522
2007	20.478930181931272
2008	22.450805008944545
2009	22.411214953271028
2010	20.21018593371059
2011	22.66715650257164
2012	24.69237079573421
2013	24.169367909238247
2014	23.86740331491713