Year	% of total fuel combustion
1985	8.65874363327674
1986	8.906249999999998
1987	4.71976401179941
1988	7.494795281054824
1989	13.230994152046785
1990	6.376360808709175
1991	11.095983662355344
1992	3.8221528861154446
1993	7.010135135135134
1994	7.864077669902912
1995	3.024390243902439
1996	2.6528258362168398
1997	4.829210836277975
1998	3.286384976525822
1999	3.4965034965034967
2000	6.570155902004456
2001	5.468749999999999
2002	6.589958158995815
2003	7.335490830636461
2004	6.932773109243697
2005	9.90909090909091
2006	5.348460291734198
2007	6.3467492260061915
2008	5.443234836702955
2009	11.14391143911439
2010	10.812720848056538
2011	9.364977549711353
2012	7.969749854566609
2013	9.056806002143622
2014	6.71806167400881