Year	% of total energy use
1990	3.263807186243751
1991	4.531408682251053
1992	5.12751034637772
1993	4.750829311678918
1994	5.356122008852479
1995	5.567135989255004
1996	5.715749789363402
1997	4.645053583821398
1998	4.675406058642007
1999	7.149552751966313
2000	6.010886243532706
2001	5.863138289764945
2002	5.2698014151790264
2003	4.040226568798762
2004	3.9944715708126433
2005	4.530795151376355
2006	3.9796313802615093
2007	3.7824445942358063
2008	3.6547659736899565
2009	4.283619991331342
2010	4.859941176195525
2011	3.4290033446155
2012	4.169129754733248
2013	4.076513905417645
2014	5.654914973822288