Year	% of total electricity output
1990	29.4517902789782
1991	31.3817128272342
1992	34.7509744478129
1993	31.8259958414512
1994	27.8222181591016
1995	30.5223705785898
1996	25.6021795222925
1997	29.1300451023476
1998	34.7855829663517
1999	30.512403357473
2000	33.4100262947296
2001	28.9275837070053
2002	26.4558735241145
2003	22.6086853402272
2004	29.8573009493855
2005	33.2492703522144
2006	27.2937117309748
2007	29.9378423287587
2008	35.8779316045046
2009	30.1086458810307
2010	29.9910751915115
2011	32.890708969946
2012	40.5618440300521
2013	35.966992716505
2014	38.5804916732752
2015	44.49903056985