Year	% of total fuel combustion
1971	41.98473282442748
1972	42.97520661157025
1973	43.84615384615384
1974	45.45454545454545
1975	44.067796610169495
1976	46.610169491525426
1977	49.572649572649574
1978	52.800000000000004
1979	53.03030303030303
1980	47.407407407407405
1981	44.966442953020135
1982	47.407407407407405
1983	44.827586206896555
1984	45.18518518518518
1985	46.76258992805756
1986	46.34146341463415
1987	46.774193548387096
1988	46.63212435233161
1989	45.8128078817734
1990	42.85714285714286
1991	42.081447963800905
1992	52.517985611510795
1993	48.333333333333336
1994	47.34299516908213
1995	46.982758620689665
1996	46.71814671814672
1997	46.54545454545455
1998	48.28767123287671
1999	49.65753424657534
2000	49.6875
2001	49.257425742574256
2002	49.4061757719715
2003	47.4835886214442
2004	48.54166666666667
2005	48.55233853006682
2006	48.75
2007	47.30983302411874
2008	44.80408858603066
2009	46.07679465776293
2010	47.81879194630873
2011	43.66812227074236
2012	46.905089408528205
2013	46.82352941176471
2014	46.87842278203724