Year	% of total fuel combustion
1985	10.611205432937181
1986	10.234375
1987	9.808259587020649
1988	14.57321304649549
1989	10.964912280701755
1990	11.975116640746501
1991	6.73927842069435
1992	6.942277691107644
1993	8.361486486486488
1994	6.5048543689320395
1995	8.097560975609756
1996	10.034602076124568
1997	9.540636042402827
1998	9.272300469483568
1999	9.557109557109557
2000	10.801781737193764
2001	10.379464285714285
2002	10.878661087866108
2003	10.787486515641856
2004	12.184873949579831
2005	9.363636363636365
2006	10.372771474878444
2007	11.91950464396285
2008	12.597200622083982
2009	10.92250922509225
2010	10.247349823321555
2011	11.032713277742143
2012	11.343804537521814
2013	10.12861736334405
2014	11.123348017621145