Year	% of energy use
1971	-45.6442670155033
1972	-54.482667949879996
1973	-60.84768319938555
1974	-67.31916369935045
1975	-51.12304183131642
1976	-58.928865569899855
1977	-58.8077409485305
1978	-50.949382846650565
1979	-64.25630730755313
1980	-57.154007103100916
1981	-39.92276592825306
1982	-35.27013962527743
1983	-36.13191315516684
1984	-42.70197494035861
1985	-47.53395659194515
1986	-45.998026526532264
1987	-41.70996309132012
1988	-44.655690381893095
1989	-50.88159037353211
1990	-52.63681146823221
1991	-51.91316469427429
1992	-55.300826062492376
1993	-54.220408231604
1994	-56.05377518283769
1995	-55.6676079526732
1996	-57.661439530738626
1997	-61.60478839226252
1998	-60.70871019874642
1999	-57.085784663467095
2000	-61.15644023903235
2001	-59.0523600632201
2002	-55.417231846751356
2003	-58.419381363574715
2004	-58.446942954958416
2005	-60.94579224929307
2006	-62.20092897835471
2007	-61.36835078836857
2008	-57.50114513318715
2009	-55.215997987340835
2010	-58.18464697702541
2011	-54.57736214103883
2012	-51.570981045586905
2013	-48.12737029537663
2014	-48.80313559733925