Year	% of total fuel combustion
1990	44.75753604193971
1991	51.52501016673444
1992	66.12903225806453
1993	61.705882352941174
1994	58.43591600289645
1995	52.14465937762826
1996	58.57002938295789
1997	55.31686358754027
1998	58.83748517200475
1999	61.06442577030812
2000	62.23241590214066
2001	63.1578947368421
2002	57.758620689655174
2003	55.851063829787236
2004	49.39919893190921
2005	49.090909090909086
2006	50.59920106524633
2007	50.3392130257802
2008	50.886766712141885
2009	52.13204951856947
2010	47.51592356687898
2011	45.12820512820513
2012	46.65792922673656
2013	41.64179104477611
2014	45.10344827586207