Year	% of total fuel combustion
1971	15.918163672654693
1972	13.981358189081226
1973	15.70807153214113
1974	14.346712211784798
1975	16.151740320688308
1976	16.38739946380697
1977	19.0997186620819
1978	20.886460230722527
1979	21.959273527793062
1980	22.710532776822983
1981	23.364084960308947
1982	24.533174413984902
1983	26.612186889323148
1984	26.667746113989637
1985	28.79751745539178
1986	31.65829145728643
1987	32.92837971464896
1988	33.38886575038178
1989	32.24656810982049
1990	32.57098805088013
1991	34.83102421338858
1992	34.50730610715624
1993	33.53695784972511
1994	34.894613583138174
1995	33.50887936313533
1996	32.54410399257196
1997	32.871116844028805
1998	35.38116134299419
1999	35.848318999218144
2000	34.53013739845552
2001	35.37757026129119
2002	37.008222084696314
2003	39.9250553568387
2004	46.09740867936309
2005	43.97040519983405
2006	43.58114770262276
2007	41.305942773294205
2008	43.74597600234124
2009	45.16424926904776
2010	44.12698412698413
2011	44.56855015330706
2012	46.584605631570604
2013	49.57128158225677
2014	50.3376233623824