Year	% of total energy
1990	1.7460091221097647
1991	1.6246976500403572
1992	2.516934336957411
1993	4.576379415260176
1994	5.35454746855357
1995	5.229212913605948
1996	5.304586674915996
1997	5.722087332677848
1998	5.99362042892185
1999	7.34321470516918
2000	8.779921404884188
2001	8.099143651909
2002	7.992370520070071
2003	8.005949064404687
2004	8.207777879470713
2005	8.864399184829603
2006	9.447618564743754
2007	8.899477860615596
2008	9.339474338949492
2009	10.128084713330008
2010	12.712282315347107
2011	12.236171440093443
2012	13.243685900459928
2013	14.30988500654857
2014	14.999633147804966