Year	% of total electricity output
1990	99.8669623059867
1991	99.8442367601246
1992	99.8680158380994
1993	99.8942246668077
1994	99.8953974895397
1995	99.8193133908854
1996	99.902400936951
1997	99.9283924095954
1998	99.9203948415857
1999	99.9304396215915
2000	99.934929724102
2001	99.9502054027138
2002	99.9287072243346
2003	99.9294117647059
2004	99.9536124318683
2005	99.9424361040755
2006	99.9597180261833
2007	99.9749519913167
2008	99.9878544968725
2009	99.9881192824047
2010	99.9882759833519
2011	99.9883795247226
2012	99.9829050088324
2013	99.9724000883197
2014	99.9834464492634
2015	99.9787222724613