Year	% of total fuel combustion
1971	45.834139898202025
1972	45.441028603213304
1973	44.47942754919498
1974	45.034991678196874
1975	45.212208370513466
1976	46.12865223457854
1977	46.32812615461921
1978	44.9456023069865
1979	43.37652205054742
1980	42.19997276458877
1981	41.082552240648006
1982	41.42593807604585
1983	41.59433653588744
1984	41.95431416172875
1985	38.76340653037371
1986	38.55058886509636
1987	38.27699489928244
1988	37.40703275744517
1989	35.8696491544184
1990	34.17243523316062
1991	33.67087715727299
1992	33.51431502797102
1993	32.93884111327857
1994	33.172647800063004
1995	35.12308575579693
1996	32.05069405337622
1997	31.289287204184205
1998	31.97986818586789
1999	28.811681318123632
2000	27.716169658870097
2001	27.954228243543174
2002	27.029603422273226
2003	26.93166666321056
2004	30.198418779918317
2005	31.371538209978077
2006	31.13213383968582
2007	31.844113276279614
2008	32.79028302810177
2009	33.06779102146028
2010	32.188827431473456
2011	31.595776613391617
2012	30.723560964224713
2013	29.7840655987191
2014	30.291897954990915