Year	% of total fuel combustion
1981	1.449275362318841
1982	1.388888888888889
1983	1.418439716312057
1984	2.1428571428571423
1985	1.333333333333333
1986	2.3121387283236996
1987	1.675977653631285
1988	1.3953488372093021
1989	1.687763713080169
1990	1.423487544483986
1991	1.0989010989010994
1992	0.9090909090909088
1993	0.9230769230769235
1994	0.9740259740259744
1995	1.2539184952978053
1996	1.3698630136986303
1997	0.9771986970684037
1998	1.0869565217391313
1999	1.0362694300518136
2000	0.9925558312655082
2001	1.550387596899225
2002	1.7369727047146404
2003	2.046035805626598
2004	2.7707808564231735
2005	0.700934579439252
2006	0.9779951100244497
2007	3.009259259259258
2008	1.3667425968109344
2009	2.3354564755838645
2010	1.2232415902140674
2011	0.78125
2012	0.8179959100204498
2013	0.7633587786259544
2014	0.7267441860465117