Year	% of total electricity output
1990	80.0061986672865
1991	77.1894521864488
1992	72.5877059646136
1993	77.0240700218818
1994	82.052164930705
1995	83.8528090510787
1996	79.0639651248869
1997	70.0935083133472
1998	75.6460704030629
1999	69.524288018616
2000	71.5010064463526
2001	63.5550389164055
2002	69.4774668340348
2003	65.9955366996101
2004	72.061846038864
2005	64.2361757587042
2006	64.4786936379065
2007	65.5749320046625
2008	64.2516704294087
2009	71.7073619773088
2010	73.1805629787992
2011	76.0402850527168
2012	71.8665281041027
2013	74.2581122307479
2014	79.2023905298242
2015	80.0814387512725