Year	% of energy use
1971	-44.51670993972014
1972	-54.3028986235705
1973	-59.820797372091505
1974	-64.45254438676612
1975	-49.20443068585762
1976	-56.491516543356894
1977	-53.41924152004352
1978	-46.19487327923568
1979	-55.11950603241477
1980	-47.72391800176657
1981	-30.649346335557727
1982	-24.93022304301417
1983	-23.139906537963146
1984	-27.597580911943528
1985	-29.164108245937395
1986	-27.47161317411987
1987	-24.227173562202335
1988	-29.157807169813942
1989	-34.87536688168434
1990	-23.10433522713942
1991	-24.84515499474132
1992	-26.537673098249208
1993	-27.920566927085314
1994	-31.48174544266772
1995	-31.842297892005167
1996	-32.34220225054068
1997	-34.118393388561806
1998	-31.328665139735172
1999	-29.73995898868293
2000	-33.97214520131643
2001	-34.59731322717692
2002	-29.747144229047596
2003	-33.53024814106148
2004	-33.26521812620448
2005	-32.25874457496758
2006	-30.727051969624505
2007	-28.748093993831596
2008	-26.216246990704878
2009	-25.732776606188015
2010	-29.565927820454533
2011	-27.49538778430744
2012	-21.943563637163297
2013	-19.754464678704604
2014	-19.04694839299262