Year	% of total fuel combustion
1971	37.05406771096513
1972	37.552660888092596
1973	38.033943134229666
1974	40.81275104691906
1975	42.231391842564676
1976	42.6879220635448
1977	42.41151331409578
1978	36.55239579275419
1979	39.00809949714023
1980	39.88433038134828
1981	41.329450059962305
1982	44.14845957681439
1983	46.205003694711294
1984	47.71010547805376
1985	47.90926301105982
1986	48.79946344735079
1987	50.76027073823389
1988	48.5757074662257
1989	49.71396936704189
1990	50.76736427054899
1991	51.588552719335475
1992	52.31557807020174
1993	54.95924317248765
1994	55.90516088777967
1995	55.60605630201971
1996	55.47907938407966
1997	55.22879177377892
1998	56.30489651691064
1999	55.70304818092427
2000	56.6018707611628
2001	59.282427868815304
2002	58.42270324802071
2003	57.925035980226525
2004	58.277704911614435
2005	56.811503959837324
2006	56.58382932673727
2007	57.11841395599693
2008	58.0021426596627
2009	53.64735607291102
2010	57.25273590749538
2011	55.78606939498718
2012	54.932480337680744
2013	53.879405896696966
2014	54.768659806462495