Year	% of energy use
1990	99.14846489057808
1991	98.88111686394208
1992	98.76386624368129
1993	98.44951437121672
1994	98.3104187959327
1995	98.10003181379541
1996	97.75501492127276
1997	97.41333274773652
1998	97.54349111622884
1999	97.16050095968059
2000	96.83440440690089
2001	96.71094600602936
2002	96.84821612010808
2003	96.68195103862203
2004	96.46097132944045
2005	96.91417525810044
2006	96.67650906654285
2007	96.72281933329283
2008	96.24101758275663
2009	95.94133944045089
2010	93.81178400691819
2011	92.52078846245765
2012	92.24741948092444
2013	90.04959890234821
2014	90.01107669269402