Year	% of total fuel combustion
1971	52.72206303724928
1972	51.98863636363637
1973	51.88916876574308
1974	42.829827915869984
1975	44.856661045531204
1976	43.00291545189505
1977	44.49938195302843
1978	45.346320346320354
1979	35.670103092783506
1980	38.36538461538462
1981	38.813559322033896
1982	40.01692047377327
1983	43.6429215509468
1984	48.479427549194995
1985	49.39965694682675
1986	49.87405541561713
1987	49.311531841652325
1988	56.3873067534581
1989	55.740432612312816
1990	58.70870870870871
1991	57.58447160316319
1992	54.8582995951417
1993	58.119658119658126
1994	58.18791946308725
1995	49.490713001797474
1996	52.44791666666667
1997	52.1781693587861
1998	48.92156862745098
1999	47.57869249394673
2000	48.20739106453393
2001	45.22821576763486
2002	45.35353535353535
2003	46.14599285349668
2004	41.96307969383161
2005	40.635451505016725
2006	39.181746656176244
2007	38.25220390954389
2008	38.31739961759082
2009	36.25304136253041
2010	39.03276131045242
2011	41.35200974421437
2012	41.152383737935075
2013	41.873431837189855
2014	41.67312161115415