Year % of total fuel combustion 1991 6.194690265486727 1992 2.4390243902439024 1993 14.685314685314685 1994 13.939393939393941 1995 2.2346368715083798 1996 2.0833333333333335 1997 2.0304568527918785 1998 2.4752475247524752 1999 2.0202020202020203 2000 0.5263157894736843 2001 0.4115226337448559 2002 0 2003 0.8928571428571428 2004 0.4273504273504274 2005 1.6064257028112447 2006 6 2007 6.563706563706565 2008 8.21917808219178 2009 3.691275167785235 2010 0.977198697068404 2011 0.6389776357827477 2012 2.7777777777777777 2013 2.3255813953488373 2014 0.2785515320334262