Year	% of total electricity output
1990	14.00096383942066
1991	14.969597253738778
1992	15.70341235442817
1993	17.398335599783188
1994	18.900801717366118
1995	19.247764445991116
1996	18.749642283491685
1997	18.792560839957684
1998	19.706346400139722
1999	19.383587785086643
2000	18.160543877508477
2001	18.02021195210898
2002	17.835913379561863
2003	16.956084003824802
2004	18.985764003932076
2005	18.41688462511852
2006	17.70839503499887
2007	16.535947482320832
2008	15.855857545720172
2009	17.564467710796972
2010	18.423443911313797
2011	16.96803198943971
2012	17.29151046942611
2013	19.20246372610945
2014	18.194991481654615
2015	19.148862073977174