Year	% of total fuel combustion
1971	48.450543167524295
1972	50.20506888211168
1973	50.227576974564926
1974	50.95656457837261
1975	51.0148954233233
1976	49.870674589304436
1977	47.267034238649515
1978	46.410945211469986
1979	45.77879966985026
1980	43.71236062250313
1981	46.784
1982	46.87920107547532
1983	46.317280453257794
1984	45.54889143473281
1985	44.858496606479704
1986	44.35414639729869
1987	42.48118204627823
1988	41.814195670046594
1989	43.13034998374688
1990	44.58616010854817
1991	44.95998326097192
1992	44.244034540902355
1993	44.381468703794965
1994	44.76235741444867
1995	45.74038292640084
1996	46.200447245375074
1997	45.8493364262083
1998	46.88077463227142
1999	44.41424688885711
2000	42.906503369710244
2001	42.80790979355572
2002	43.55715052320902
2003	43.54651162790698
2004	43.98101817477484
2005	44.10305958132045
2006	44.56899022386397
2007	44.18153136755248
2008	43.41314783408549
2009	45.76422714100746
2010	45.2513966480447
2011	47.15726789701994
2012	47.57483895414929
2013	46.09930649413955
2014	44.75232133103651