Year	% of energy use
1971	-41.699411695534685
1972	-53.634234688017756
1973	-72.518525326366
1974	-49.218272921797706
1975	-47.19517468873825
1976	-41.39046544243328
1977	-37.40696474986379
1978	-34.85332287856237
1979	-50.5439748153341
1980	-12.258245573824619
1981	-0.07642915284533199
1982	1.129029561418009
1983	0.8518419425188566
1984	-2.264095056827232
1985	-3.8158615248284464
1986	-3.3111957715540883
1987	-2.519563775127922
1988	0.42061067785824424
1989	-0.6568520726418212
1990	7.9650583526857
1991	-2.7836238308042405
1992	-3.3762506506807206
1993	-0.09775597074082878
1994	9.33073227807364
1995	6.6359163452851755
1996	6.29130250916267
1997	8.699857038204922
1998	18.412902935822437
1999	40.249672431244065
2000	45.002409149414106
2001	51.68878420558779
2002	53.04410091701662
2003	49.01463468114383
2004	46.00381618053157
2005	47.76617094727826
2006	42.377003843408296
2007	47.998391442951934
2008	45.219326532044356
2009	41.667245837086284
2010	23.71398494003414
2011	33.26028861811847
2012	16.297868608016845
2013	12.320705333450574
2014	13.797970897965639