Year	% of total energy use
1960	23.68182360455359
1961	23.501717207633558
1962	20.818427366143617
1963	18.194603308524705
1964	18.003202468099214
1965	18.664014909719555
1966	20.44025168040108
1967	20.952483447689204
1968	19.134612313874985
1969	17.30452357171199
1970	19.734289610440648
1971	16.314413028671048
1972	18.181504649513734
1973	21.386555797286427
1974	23.96367810744455
1975	28.52546344579444
1976	24.18744792089967
1977	28.711305284744043
1978	26.20210120054251
1979	30.24259859187514
1980	32.754649593534886
1981	35.90269854728048
1982	37.12083299756364
1983	35.11128645604556
1984	35.521615727053025
1985	39.16479946752215
1986	37.88026300499293
1987	40.065867708011915
1988	39.882264625342366
1989	38.44560076205945
1990	35.049563087188815
1991	34.44305685881606
1992	34.83084034731406
1993	35.96953535521853
1994	36.83784782855357
1995	37.668062184303416
1996	36.510602278463224
1997	36.76152530583269
1998	36.819952522230324
1999	38.027660407064836
2000	39.01811702573521
2001	37.76178246798469
2002	38.532507976631756
2003	38.79477765972617
2004	38.30316259896165
2005	35.460892220695634
2006	37.66311480330503
2007	40.332372887344455
2008	39.074028154551364
2009	38.747986157265096
2010	39.43492772938333
2011	40.28377379899947
2012	39.9044022359133
2013	38.86709122930509
2014	42.422824147012214
2015	39.88653588399649