Year	% of total fuel combustion
1971	38.51722634103793
1972	39.96788370520622
1973	39.933379812533886
1974	41.658318563612546
1975	35.01458348153945
1976	36.46077664842325
1977	35.31205276585153
1978	33.03888952621315
1979	30.007833482542523
1980	23.02357054246081
1981	31.766286098052387
1982	31.731368659676967
1983	33.514269725797426
1984	34.61406518010291
1985	37.748041402184484
1986	40.083333333333336
1987	37.98379837983798
1988	39.28479281696682
1989	43.91130306541661
1990	47.192680173489386
1991	48.857858933046906
1992	68.87812752219531
1993	71.50195907705704
1994	62.02385190459238
1995	59.267131440231246
1996	59.24394077260319
1997	57.36665761115639
1998	57.02736318407959
1999	57.680704718233365
2000	57.38636363636365
2001	56.162434325744314
2002	54.71843378794544
2003	55.89690721649484
2004	52.815699658703075
2005	52.48219296352256
2006	53.04238355014688
2007	53.16825259515571
2008	52.74520547945205
2009	52.471924615980384
2010	51.84590690208668
2011	54.06674907292954
2012	50.65513293474112
2013	46.21739130434783
2014	45.58392018779343