Year	% of total fuel combustion
1971	1.7699115044247784
1972	1.6064257028112445
1973	2.661596958174906
1974	1.8450184501845017
1975	2.6578073089701
1976	2.7586206896551726
1977	2.3952095808383236
1978	2.933333333333333
1979	2.6128266033254155
1980	1.9002375296912104
1981	2.2038567493112953
1982	2.507836990595612
1983	2.1818181818181817
1984	2.5889967637540456
1985	2.2012578616352205
1986	3.448275862068966
1987	3.308823529411764
1988	2.413793103448276
1989	2.6315789473684217
1990	2.4922118380062317
1991	2.6392961876832826
1992	1.8957345971563972
1993	1.9438444924406055
1994	2.0325203252032527
1995	1.877133105802048
1996	1.9230769230769236
1997	2
1998	1.7015706806282722
1999	1.8641810918774968
2000	1.631701631701632
2001	1.6685205784204677
2002	1.7616580310880838
2003	1.799505680473866E-16
2004	-9.147955830346444E-16
2005	8.167248003657285E-17
2006	8.159564797633146E-17
2007	7.562002946716683E-17
2008	8.46206573647223E-17
2009	0.08904719501335624
2010	1.68093360075272E-16
2011	8.276352461721408E-17
2012	1.6380769367108658E-16
2013	1.419577312583312E-16
2014	1.0747976926746015E-16