Year	% of total fuel combustion
1990	1.511627906976744
1991	1.6686531585220505
1992	1.6786570743405282
1993	1.61849710982659
1994	4.425837320574163
1995	4.687499999999999
1996	2.836879432624114
1997	2.159090909090909
1998	1.4492753623188408
1999	1.2373453318335212
2000	1.5240328253223916
2001	1.1520737327188941
2002	0.7371007371007371
2003	0.4524886877828052
2004	1.8713450292397662
2005	0.7865168539325836
2006	0.6741573033707865
2007	0.42826552462526746
2008	0.5476451259583786
2009	0.35211267605633767
2010	0.5995203836930455
2011	0.545851528384279
2012	0.454029511918275
2013	0.5082592121982212
2014	0.5383580080753698