Year	% of energy use
1990	49.26374208831057
1991	44.45205180364445
1992	43.13455796190606
1993	45.4181452310888
1994	38.82877266688821
1995	36.17931581848716
1996	43.26256425808565
1997	40.69143917386102
1998	39.49984198941727
1999	39.757562831565174
2000	42.47143425849775
2001	38.870525244222236
2002	40.13179995370581
2003	40.26327232109731
2004	41.82193282656323
2005	45.79930152901661
2006	44.8426933224844
2007	50.29959378738311
2008	46.23485789011936
2009	42.902091443835076
2010	43.88030560183203
2011	44.36738597280936
2012	48.500888802440016
2013	49.648799096197834
2014	51.77099873997075