Year	% of total fuel combustion
1986	47.10293115201091
1987	47.801418439716315
1988	49.6764917325665
1989	49.82001439884809
1990	46.75036927621862
1991	42.8235294117647
1992	47.95180722891567
1993	45.48192771084338
1994	42.630385487528336
1995	42.217484008528785
1996	38.088829071332434
1997	39.04512753433617
1998	42.192691029900324
1999	38.339100346020764
2000	40.3271692745377
2001	41.397849462365585
2002	42.94234592445328
2003	41.282565130260515
2004	41.01049868766404
2005	40.84142394822006
2006	40.79696394686906
2007	41.62436548223351
2008	37.97619047619047
2009	40.410052910052904
2010	40.25889967637541
2011	40.82955281918341
2012	40.484196368527236
2013	40.85794655414908
2014	35.658307210031346