Year	% of total energy use
1971	1.4861214272686663
1972	1.6198817618850199
1973	1.5699139585398258
1974	1.2609926564041334
1975	1.1974315695497435
1976	1.0402414777022666
1977	0.8367267024675807
1978	0.7581485770890483
1979	0.7894204657075172
1980	1.0094031652393216
1981	1.0499335988537397
1982	0.9966909803412446
1983	0.9953786800837108
1984	1.9042836375797876
1985	2.064795784353299
1986	2.0111030818940803
1987	2.395819670329994
1988	2.63512486188609
1989	2.2186960322000395
1990	1.3615788672887743
1991	1.186579548510835
1992	1.1109875772549558
1993	1.070295615387104
1994	1.5313441770060756
1995	1.3363921930906837
1996	0.9962764033259414
1997	0.6589941832982619
1998	0.865094794169647
1999	1.2958588392187373
2000	1.0829412173072384
2001	1.0918511358309322
2002	0.8047497614999684
2003	0.7220478299171854
2004	0.7769608287985617
2005	0.6635623440840309
2006	0.7893420739979846
2007	0.7068177482270765
2008	0.805482309280532
2009	0.7390976563204817
2010	0.6744236075725395
2011	0.7424723536284848
2012	0.9058482201295329
2013	0.9711568092998266
2014	1.1806877245614686