Year	% of energy use
1960	6.708588298786964
1961	6.486087667119927
1962	6.160893148062033
1963	6.616458068928041
1964	6.764508236163607
1965	7.550378811804986
1966	7.250725936840983
1967	4.56269270596814
1968	5.660685619717751
1969	7.256678533024503
1970	5.594708599353543
1971	7.899415411973599
1972	9.777975131921306
1973	12.42973907215358
1974	12.56670724431005
1975	12.327579589431826
1976	17.382933810110686
1977	18.295766298526303
1978	19.51619154471733
1979	15.90020467297679
1980	11.829419100981932
1981	9.99830128186501
1982	6.978285539075183
1983	10.053744411122647
1984	6.531198430923807
1985	7.95254213036991
1986	8.642082201301625
1987	10.053159706055423
1988	11.227911845820142
1989	12.66629311902074
1990	9.283326910088245
1991	9.873503361078484
1992	11.020510122339905
1993	13.96284036068165
1994	12.028419985484215
1995	12.602772546115448
1996	13.297733585775585
1997	14.015157296041071
1998	14.04521166981367
1999	17.116021027837462
2000	19.18582572366856
2001	16.646908486434363
2002	18.530486241866043
2003	19.910121377421635
2004	20.635414452958457
2005	21.417777636527582
2006	19.41573236260908
2007	20.102127100597162
2008	17.175212912811038
2009	14.311466748723445
2010	14.351093030028691
2011	10.66349772501931
2012	7.411837020956988
2013	5.266397296550543
2014	0.5646972039449443
2015	-1.5525628183846358