Year	% of energy use
1990	85.70866556265547
1991	84.81823243544211
1992	82.30413022645465
1993	77.63299624250226
1994	72.24873397451674
1995	68.84855568244443
1996	68.24555963309244
1997	63.35753963256797
1998	59.10135071139315
1999	58.727400398083354
2000	63.23000899058794
2001	62.962530567015406
2002	60.497099496002136
2003	59.832174333334095
2004	58.38008444378252
2005	58.90859662353981
2006	60.62378371346342
2007	62.43545283561346
2008	60.987363918789974
2009	52.36319458828916
2010	56.14114653491664
2011	51.251846512956604
2012	47.09094713728218
2013	50.60951568499627
2014	45.16008774809908