Year	% of energy use
1960	-14.359811407811822
1961	-12.839164755050467
1962	-9.318993828830532
1963	-11.12462054623463
1964	-13.024583773280645
1965	-11.365583137977614
1966	-10.977536992128767
1967	-9.997301743980195
1968	-9.833701667954147
1969	-9.13435943272085
1970	-8.124282275562745
1971	2.685309575120038
1972	2.6758964154464397
1973	5.152899526353139
1974	5.908171140716187
1975	7.660236762766262
1976	10.135460775002645
1977	12.477997669560967
1978	13.744811082977591
1979	13.919281420481736
1980	18.53006298390305
1981	21.231962887379446
1982	17.169015110428237
1983	16.384963337479814
1984	14.590736420821457
1985	17.137359530067243
1986	18.711965088495866
1987	21.270329225648148
1988	21.06717257765752
1989	23.505544333291727
1990	-12.1867825886767
1991	-8.461874212092317
1992	-10.972335469474617
1993	-11.30192507260812
1994	-15.781257754128637
1995	-15.28333592630502
1996	-16.075899305548173
1997	-16.86774300560645
1998	-19.105110496837415
1999	-21.1115967704287
2000	-23.59822296705522
2001	-26.609145498418126
2002	-29.64114616257365
2003	-32.29925489534886
2004	-36.139194038755726
2005	-38.86188824574409
2006	-37.94328112287728
2007	-38.80470401729396
2008	-39.851072688960116
2009	-42.84251693236628
2010	-41.75947718981264
2011	-39.37928924258964
2012	-39.68780971913296
2013	-44.72613849895458
2014	-44.91619288549539
2015	55.52708265300989