Year	% of total energy use
1971	7.56665451737936
1972	7.234058771963259
1973	7.005411276271759
1974	6.958418822881307
1975	6.237953153893014
1976	5.970679325391418
1977	5.8956343454401
1978	5.758780526073648
1979	5.3422470612955655
1980	3.7397468681696076
1981	3.8743192291579387
1982	3.6496472106532485
1983	3.840614760919797
1984	3.921981928260767
1985	3.897247458864659
1986	4.0216674026822306
1987	4.134266940816451
1988	4.336808804565664
1989	4.085148161007639
1990	3.02602728654163
1991	3.5455404423718258
1992	3.2374457938177676
1993	3.6103273035847065
1994	2.9282394427288327
1995	2.5269493059842723
1996	2.654837005628709
1997	2.682015103009977
1998	2.628089958151494
1999	3.0887074725362944
2000	3.0515250817819934
2001	4.292365771965951
2002	3.6747129499179736
2003	3.139617147448498
2004	3.407816789636013
2005	2.8405666020261555
2006	2.4696178275270193
2007	3.250371280633107
2008	3.3194525538245685
2009	3.1457882464252416
2010	2.6515752172186104
2011	2.6247937501934997
2012	2.2530163723286156
2013	2.4160292594694783
2014	1.9749792743831616