Year	% of total fuel combustion
2000	6.8493150684931505
2001	6.635802469135801
2002	6.666666666666667
2003	6.637168141592921
2004	5.985401459854015
2005	6.7669172932330826
2006	6.855439642324888
2007	6.534090909090909
2008	6.464379947229551
2009	5.35077288941736
2010	6.659012629161881
2011	7.88863109048724
2012	7.011070110701106
2013	6.738868832731648
2014	5.945945945945946