Year	% of energy use
1971	58.284087013451526
1972	58.42525013964247
1973	60.98044624020634
1974	59.19864910032564
1975	61.106985260496394
1976	59.44001243575359
1977	64.92202974322629
1978	65.53390493502835
1979	64.90635906844541
1980	60.47466307213284
1981	56.106880579231664
1982	54.16365015865456
1983	49.23328506670601
1984	48.82820739389448
1985	52.62895133898301
1986	53.83864136201918
1987	55.73067099938098
1988	55.67758350099212
1989	59.14331351803871
1990	59.3493749079695
1991	59.494607513748086
1992	58.85796962708324
1993	58.302678701648055
1994	57.37456781103322
1995	59.389898979616085
1996	57.70607381226521
1997	58.43798784727219
1998	63.757671909286586
1999	60.590171118507065
2000	57.60555459662915
2001	56.46518398493403
2002	53.8170966049062
2003	56.38651682914858
2004	47.46354156161123
2005	46.91544755700797
2006	47.90322341565485
2007	49.374818673904045
2008	48.86697270912998
2009	48.102656841713845
2010	47.56954062732655
2011	48.1964316173125
2012	47.91574481788917
2013	49.04993582405383
2014	49.834183800871344