Year	% of total electricity output
1990	64.91514474939267
1991	64.07681443874745
1992	61.45274752235563
1993	61.6141552829195
1994	60.83560987068489
1995	57.83926473644016
1996	57.68792416062175
1997	55.24260297390376
1998	58.8096533215158
1999	58.44609552024879
2000	59.3300114589239
2001	59.953853726819354
2002	59.546920932782434
2003	57.42162984656534
2004	55.0602779483059
2005	55.10912121436822
2006	54.52648211431915
2007	54.95316751677841
2008	53.23250491504633
2009	54.07802202836726
2010	54.57076403227016
2011	54.88211132972261
2012	52.509214925006056
2013	52.76723801283804
2014	51.93378273877497
2015	52.17812439304692