Year	% of energy use
1971	11.187984667610834
1972	11.050519483647056
1973	11.400975326597894
1974	12.046892523277878
1975	11.161527804734412
1976	-6.178955385319867
1977	-4.224712196881263
1978	-0.7928305686322757
1979	-0.6447979850986241
1980	-1.3648606094022804
1981	-0.6776019538934445
1982	-4.165484638354426
1983	-1.9530480113394324
1984	-3.3038785945868407
1985	-7.083880234476915
1986	-7.480037325323216
1987	-5.487745312413033
1988	-3.7054387939870237
1989	-4.067780376142439
1990	-1.8684751927326753
1991	-2.8504200172527403
1992	-2.9339456732089038
1993	-2.9105540082488472
1994	-6.034691736075398
1995	-6.284385897542879
1996	-6.2189006369511155
1997	-5.960349979089644
1998	-5.479744424638513
1999	-6.585602459552415
2000	-7.2154727970477035
2001	-7.752470825268857
2002	-6.926140314086565
2003	-7.1189078438121225
2004	-7.4097476631535155
2005	-5.98119406399462
2006	-5.2157546036618925
2007	-4.605349707314968
2008	-3.463890856489677
2009	-3.4370854509966846
2010	-2.8703535435953764
2011	-2.116756238245152
2012	-1.5471374201008912
2013	0.22473173304265592
2014	1.9592673013969177