Year	% of total energy
1990	2.326879461285603
1991	2.585100892565961
1992	3.6703770312093646
1993	4.405577179956838
1994	11.378672140994606
1995	10.388251009913075
1996	9.16210566847273
1997	6.11357569059051
1998	5.067948402871365
1999	5.276302071152781
2000	4.1318107877401795
2001	4.325560709369195
2002	4.143278460457827
2003	4.1479114955209235
2004	3.7852156240239974
2005	3.6052347064282237
2006	3.4238199864340775
2007	3.4158194267589175
2008	3.0144343120852373
2009	2.8884206115992512
2010	2.7598210829356393
2011	2.5005578295420707
2012	2.6705833773561958
2013	2.7565856637213115
2014	17.820211252340236