Year	% of total energy use
1960	4.656268618282236
1961	6.865687057777197
1962	7.9208962447625
1963	6.421879828429525
1964	5.884521389726663
1965	6.104140162332109
1966	6.357657640912971
1967	6.9453296978412755
1968	5.832907045775168
1969	4.433731115581505
1970	4.463775929199253
1971	5.030358105099424
1972	4.568726584888997
1973	4.299463129330594
1974	5.2826847596947575
1975	5.304301263554855
1976	3.8499609836837494
1977	8.109183150012168
1978	7.616424136165387
1979	11.382068649642525
1980	11.011019874051962
1981	21.09253682167245
1982	23.70039279098709
1983	24.700410453016442
1984	25.26263540368375
1985	23.331679704861376
1986	22.371710750175275
1987	21.45061090615425
1988	22.58322681078804
1989	21.340269997759354
1990	21.246201660731455
1991	21.709405526591745
1992	23.491750616381513
1993	22.43205875866904
1994	19.995368538922477
1995	21.257156802104134
1996	19.539389100513404
1997	20.271127884835693
1998	21.676029118388858
1999	22.15735803832349
2000	22.5048819298451
2001	21.63236900179278
2002	19.64866422365819
2003	18.455210482503027
2004	19.526133877465014
2005	21.972851697105348
2006	19.028278941169482
2007	20.442166489428786
2008	21.794277801665928
2009	22.29605826249054
2010	19.822416618887594
2011	21.009507730074642
2012	23.26400772914681
2013	23.15159690577665
2014	23.170870691766755
2015	25.35131372106546