Year	% of total electricity output
1990	11.8029294274301
1991	11.1344964460445
1992	12.3372159258314
1993	14.9708030682211
1994	14.9707112970711
1995	13.0402714264641
1996	14.3662343952971
1997	12.5439701220307
1998	12.5446623093682
1999	12.5451820506039
2000	12.5448105155343
2001	12.5456099747712
2002	12.5451226931657
2003	15.4251012145749
2004	18.02
2005	17.5406504065041
2006	17.9890023566379
2007	13.0745658835546
2008	22.995951417004
2009	18.6786786786787
2010	20.9787234042553
2011	19.5419847328244
2012	21.352380952381
2013	21.3284132841328
2014	21.3537906137184
2015	20.6529329608939