Year	% of total fuel combustion
1971	37.05406771096513
1972	37.55266088809259
1973	38.033943134229666
1974	40.81275104691907
1975	42.23139184256467
1976	42.68792206354478
1977	42.41151331409578
1978	36.55239579275419
1979	39.00809949714023
1980	39.884330381348285
1981	41.329450059962305
1982	44.14845957681439
1983	46.205003694711294
1984	47.71010547805376
1985	47.90926301105982
1986	48.79946344735078
1987	50.760270738233906
1988	48.5757074662257
1989	49.71396936704188
1990	50.767364270548995
1991	51.588552719335475
1992	52.31557807020173
1993	54.95924317248765
1994	55.90516088777966
1995	55.60605630201972
1996	55.47907938407966
1997	55.22879177377894
1998	56.304896516910645
1999	55.70304818092429
2000	56.6018707611628
2001	59.2824278688153
2002	58.42270324802072
2003	57.92503598022652
2004	58.277704911614435
2005	56.811503959837324
2006	56.58382932673727
2007	57.11841395599694
2008	58.0021426596627
2009	53.64735607291104
2010	57.25273590749535
2011	55.78606939498718
2012	54.932480337680744
2013	53.879405896696966
2014	54.7686598064625