Year % of energy use 1960 40.52218500967774 1961 42.08291926048152 1962 40.95322358029753 1963 40.048171473037584 1964 42.27563320404097 1965 44.18341710888378 1966 45.65778199285159 1967 48.040142765614156 1968 49.92849487477307 1969 51.01845422807937 1970 52.22448379003058 1971 51.18998291477085 1972 50.74912098383495 1973 50.3761893592787 1974 50.1076758604374 1975 46.28613293463854 1976 42.6170455668134 1977 38.25930000889592 1978 36.979242621569064 1979 40.09668271614885 1980 39.106481385641004 1981 35.2024271495814 1982 29.7196862966637 1983 27.421639961663942 1984 23.88772072966847 1985 20.066862152383298 1986 12.159464745660387 1987 14.408996123516435 1988 12.114385516399091 1989 9.673488385946689 1990 10.183479104534833 1991 7.904175384578899 1992 8.4344784121274 1993 9.163307824239128 1994 14.042114668116628 1995 15.02605597392273 1996 11.162091233144292 1997 10.170491299574135 1998 15.823022809275736 1999 16.153758435149108 2000 16.37860002843687 2001 16.12910373827049 2002 14.554768214940584 2003 21.201504920272935 2004 23.580332601789127 2005 24.026251657519396 2006 21.72167331595184 2007 17.58464164524037 2008 13.913424222116614 2009 12.671970705110272 2010 8.144425569217557 2011 11.981943067090148 2012 16.45899945865781 2013 16.41409443946654 2014 17.084552590758506 2015 19.47815263060601