Year	% of total electricity output
1990	45.4248490143199
1991	42.5084798627627
1992	39.1959798994975
1993	40.2460589186952
1994	39.9789964228283
1995	36.8438300661384
1996	36.9319574155254
1997	33.434681006106
1998	33.62355091635
1999	44.4921799575208
2000	42.8902627511592
2001	37.2922422954304
2002	35.6428085088823
2003	33.4189648658859
2004	33.7312579301964
2005	32.365159898881
2006	36.0283887783315
2007	31.5998725067521
2008	33.9159171996514
2009	32.5850680706061
2010	26.2983082873254
2011	28.6558922169539
2012	28.4444810136998
2013	26.4036882523317
2014	25.5973182159406
2015	25.4134663220608