Year	% of total energy
1971	6.179223202657045
1972	4.60616843523052
1973	4.057952941140245
1974	3.7832935735461737
1975	3.106221556909103
1976	3.5363487900381463
1977	2.9346073749530914
1978	2.668880844233462
1979	2.381197687056356
1980	1.7738383108274418
1981	1.642467821168625
1982	1.5113328813533098
1983	1.4801211266468561
1984	1.379063135737396
1985	1.2340112025825845
1986	1.2398158620198658
1987	1.1357872354650191
1988	1.1816147190962287
1989	1.0883214515594855
1990	1.1196390105312475
1991	1.1036551006314268
1992	1.1092335469072472
1993	1.0687137212051756
1994	0.9464938336648892
1995	0.8939910994132888
1996	0.8600889179903447
1997	0.8647710611316991
1998	0.8733064799446796
1999	0.904483706849051
2000	0.8817162669843553
2001	0.8754088215306602
2002	0.8520286434177753
2003	0.8376892958943202
2004	0.8243072897608064
2005	0.8417706103067613
2006	0.8428127296459755
2007	0.917709745811404
2008	0.8708948464914745
2009	0.8088857213668917
2010	0.7524525435027413
2011	1.138083754793068
2012	0.8952126692467245
2013	0.7865723189876198
2014	0.8463503045880613