Year	% of total energy
1990	0.007673340834142614
1991	0.007549735442087446
1992	0.008228767421874592
1993	0.008113982232481198
1994	0.00835330532371902
1995	0.00927347233638281
1996	0.009130739360262303
1997	0.00913516053893577
1998	0.008363396397891777
1999	0.006376809865610876
2000	0.008120986380392232
2001	0.00807110323482237
2002	0.007301186414653174
2003	0.006672690262041921
2004	0.006204602271608827
2005	0.0076584927300494075
2006	0.007843857629555872
2007	0.008298266319669064
2008	0.00757911801725291
2009	0.0085351461051649
2010	0.008731812840754484
2011	0.007968620573276039
2012	0.007892510818998475
2013	0.009066016298796515