Year	% of total electricity output
1990	31.1538461538462
1991	30.1050175029172
1992	32.6881720430108
1993	27.7047522750253
1994	22.8053435114504
1995	26.843910806175
1996	25.923016496465
1997	24.517512508935
1998	27.6332899869961
1999	20.7570977917981
2000	29.6400449943757
2001	28.7284144427002
2002	27.5897435897436
2003	27.2334293948127
2004	27.3441108545035
2005	25
2006	22.2553191489362
2007	22.393509127789
2008	23.2303480641377
2009	23.6321303841676
2010	24.3213090368167
2011	20.2123764188942
2012	20.7007508044333
2013	20.6024930747922
2014	20.2928157984338
2015	22.7227227227227