Year	% of total electricity output
1990	16.526299346626917
1991	16.233542227362918
1992	16.022607121318824
1993	16.47102650220603
1994	15.715659472220095
1995	16.14741637303034
1996	16.038450956945525
1997	15.956654525739166
1998	15.25419285721345
1999	14.980535164645708
2000	14.790426424451441
2001	14.11435134654812
2002	14.323902056196125
2003	14.09733842556621
2004	14.227387261803923
2005	14.33962445708797
2006	14.608760049316318
2007	14.5569946745527
2008	15.36254735537762
2009	16.41767761887982
2010	16.555159483315464
2011	17.785900935077247
2012	18.682337216666735
2013	19.910458876769717
2014	20.720461877485594
2015	21.25753492409252