Year	% of total fuel combustion
1971	54.77064220183486
1972	53.85281385281385
1973	45.884923525127455
1974	48.33333333333333
1975	37.770382695507486
1976	45.606326889279444
1977	44.20970266040688
1978	41.84782608695652
1979	42.1826625386997
1980	44.61657629744384
1981	47.376093294460645
1982	48.05401111993647
1983	47.082990961380446
1984	47.20133667502089
1985	50.265017667844525
1986	49.422222222222224
1987	51.30581297388374
1988	49.48371723590151
1989	45.14038876889849
1990	44.45178335535007
1991	46.40479360852196
1992	55.50715619166148
1993	62.46867167919799
1994	57.18692165330043
1995	62.70368135184067
1996	60.023174971031295
1997	60.26563364692861
1998	60.2428722280887
1999	59.15712799167534
2000	54.754098360655746
2001	55.353272648461214
2002	57.52799668187474
2003	62.56065696155282
2004	57.78508771929825
2005	56.701730573464545
2006	55.26315789473684
2007	50.08625646923519
2008	49.98468606431854
2009	54.93296665520797
2010	57.765579593154676
2011	60.17868538608808
2012	57.56791720569211
2013	57.196029776674926
2014	54.958294717330844