Year	% of total electricity output
1990	31.394004163111024
1991	32.029578351164254
1992	33.35660844848691
1993	32.057749811964555
1994	34.02843751148157
1995	32.8235873728721
1996	31.462962922882774
1997	30.8943062099821
1998	30.784727081689084
1999	28.90952529416314
2000	26.377751162077065
2001	26.9241512920813
2002	29.30299830133438
2003	32.753082182923634
2004	31.313194200567477
2005	32.339582309269325
2006	32.234495038251836
2007	29.872286194917425
2008	32.666376428597964
2009	30.11360787282582
2010	33.19272935796114
2011	30.488826194675916
2012	31.64155819070424
2013	31.012978262999138
2014	31.53696615453356
2015	31.605272785527085