Year	% of total energy use
1971	3.903824616266928
1972	3.637083981203002
1973	1.7284040937125662
1974	2.8840943342596623
1975	3.178968535604447
1976	2.9653229615990675
1977	3.791795172515658
1978	3.181786860052713
1979	3.137275771690442
1980	2.9553192917259956
1981	3.100716006651057
1982	3.1295189778173644
1983	2.4886175202600644
1984	2.54892016676656
1985	2.1603669918596546
1986	1.863779974891602
1987	1.9692088705239537
1988	2.606763642315655
1989	2.1926123242149558
1990	1.9659875786569903
1991	1.7923097407634685
1992	2.2587288891899515
1993	1.5333713635558228
1994	1.5772112595858971
1995	1.283909478684164
1996	1.4138948158519289
1997	1.3840237354657696
1998	1.2693155681219326
1999	0.5603851228973934
2000	0.8652623957266415
2001	0.6192015765675855
2002	1.1176767410084136
2003	2.071265606100653
2004	1.7516646986292583
2005	1.7690732391679047
2006	1.360757756878113
2007	1.3666389356397974
2008	0.7530114383170916
2009	0.9668862890249088
2010	1.3221508409755007
2011	1.2872308643539327
2012	1.4015153097687587
2013	1.7455868791645872
2014	0.5234493940524191