Year	% of total fuel combustion
1990	2.807895468445928
1991	3.3405505722239397
1992	2.4040489245044285
1993	2.36653824986241
1994	1.1911514463981852
1995	1.06516290726817
1996	1.2411347517730493
1997	1.0303030303030307
1998	1.1306532663316582
1999	0.5369127516778527
2000	0.689179875947622
2001	1.5364061456245823
2002	1.7844886753603295
2003	1.6304347826086962
2004	1.4440433212996393
2005	1.3674197384066586
2006	1.3522215067611079
2007	1.1375387797311272
2008	1.2950450450450448
2009	1.490514905149051
2010	1.1796246648793565
2011	1.5245623941276116
2012	1.5815085158150843
2013	1.4316012725344647
2014	1.883561643835617