Year	% of total fuel combustion
1990	11.043668858539874
1991	11.390298355997565
1992	14.033836522841636
1993	11.302256751757307
1994	9.951656037852295
1995	12.61435608726249
1996	12.100364225010116
1997	12.123865626492597
1998	12.334320910650243
1999	13.037100949094047
2000	7.928571428571429
2001	4.183449285975833
2002	2.40026762565861
2003	3.7094739965872843
2004	3.674612389864081
2005	5.57715596915036
2006	8.69716070086162
2007	10.646936267963031
2008	3.0837387074357197
2009	4.7804637395165255
2010	4.654213216337237
2011	1.2989225331118783
2012	3.3785228584869356
2013	2.1264644519338782
2014	1.3009075059233755