Year % of total electricity output 1990 76.3841901146959 1991 75.6826169234928 1992 68.6650072850899 1993 73.2539744287974 1994 78.4925982274385 1995 76.4046259013016 1996 82.9920206632535 1997 71.6444344804394 1998 69.7463082165846 1999 79.8608192050815 2000 75.5246376811594 2001 74.3381980571797 2002 76.5041516806536 2003 78.7885950022561 2004 81.650877933989 2005 80.1696565150883 2006 80.6007625778852 2007 81.533391279154 2008 84.0108691765884 2009 72.8779156240704 2010 72.1206919763059 2011 83.46528973035 2012 79.5501941031153 2013 73.9986754585505 2014 74.0383106787808 2015 68.236811220424