Year	% of total fuel combustion
1990	0.17703591299949417
1991	0.24355591637913537
1992	0.19810610563017556
1993	0.1757306696263411
1994	0.2211479119522732
1995	0.17006802721088432
1996	0.12815324430055308
1997	0.15921031682853048
1998	0.16372992359270233
1999	0.1553062985332183
2000	0.9999999999999999
2001	1.135115342365434
2002	0.9785063142928828
2003	1.2315453668669782
2004	0.7854654736698312
2005	0.6501370386895278
2006	0.7517492627074539
2007	0.4807949142582403
2008	8.478109798471161
2009	7.192895905278738
2010	7.481116287484735
2011	9.582215408202376
2012	7.07351494675619
2013	7.233991333654309
2014	10.581608476015916