Year	% of total electricity output
1990	67.6293622141998
1991	58.0262225372077
1992	65.753781950965
1993	73.2925586136595
1994	74.4369369369369
1995	73.8125157074642
1996	59.532949456174
1997	65.5792276964048
1998	74.4868035190616
1999	67.1289537712895
2000	68.2543520309478
2001	66.3317757009346
2002	62.5157232704402
2003	58.8176100628931
2004	68.1595222862017
2005	69.5882592743579
2006	56.9617665099162
2007	59.2747851603437
2008	60.902540766022
2009	63.8534745914886
2010	54.8513656254716
2011	50.4922874958976
2012	66.6288308740068
2013	56.9173779996779
2014	54.5419179148026
2015	50.1716970901862