Year	% of total electricity output
1990	16.36204443471599
1991	20.07813508218262
1992	19.528348529969758
1993	19.60170826957773
1994	19.039454243656852
1995	20.366796448592687
1996	19.91887990533058
1997	19.546957622141093
1998	20.42774018027438
1999	22.2382283960913
2000	22.841800195156907
2001	22.81769473473328
2002	22.89437998073061
2003	21.91550753281481
2004	21.10518285169116
2005	22.104634690091665
2006	23.64589511541183
2007	25.12724183548675
2008	28.350432918472666
2009	29.369988765154343
2010	27.970515440537923
2011	26.40219986896303
2012	26.193350330692866
2013	26.533954450479442
2014	25.127350519702787
2015	25.800730496873108