Year	% of total fuel combustion
1971	44.95412844036697
1972	44.16666666666667
1973	45.059288537549406
1974	45.62043795620438
1975	46.8944099378882
1976	47.30878186968839
1977	51.2
1978	53.07125307125307
1979	53.31695331695331
1980	50.1187648456057
1981	44.5916114790287
1982	34.08624229979466
1983	35.62753036437247
1984	37.47276688453159
1985	40.37122969837587
1986	41.92771084337349
1987	45.51724137931035
1988	46.948356807511736
1989	45.1271186440678
1990	43.300970873786405
1991	45.26112185686654
1992	42.69870609981516
1993	47.42451154529307
1994	45.57377049180328
1995	44.847605224963715
1996	49.45904173106646
1997	46.53312788906009
1998	45.10086455331412
1999	47.85932721712538
2000	41.26760563380282
2001	42.143906020558006
2002	40.83916083916084
2003	39.769820971867006
2004	39.7887323943662
2005	39.02976846747519
2006	39.91894630192503
2007	40.96385542168675
2008	42.07836456558774
2009	41.612903225806456
2010	39.48905109489051
2011	39.94620040349698
2012	37.83622235505081
2013	41.39562389118864
2014	40.7103825136612