Year	% of total electricity output
1990	67.7304964539007
1991	67.9802955665025
1992	67.9943100995733
1993	68.3453237410072
1994	68.7045123726346
1995	69.037037037037
1996	70.3703703703704
1997	72.3880597014925
1998	74.4360902255639
1999	73.7226277372263
2000	74.9890940817217
2001	72.8114599913182
2002	79.0639711991138
2003	70.2497285559175
2004	70.8908406524467
2005	74.0618101545254
2006	70.7557502738226
2007	72
2008	68.6548223350254
2009	87.1766029246344
2010	85.9865470852018
2011	82.4875621890547
2012	85.9099804305284
2013	78.6364080993837
2014	85.3235490326885
2015	86.0501112508465