Year % of total fuel combustion 1960 0.8547008547008548 1961 0.8695652173913043 1962 0.8064516129032258 1963 0.7874015748031495 1964 0.7751937984496123 1965 1.4285714285714286 1966 2 1967 1.4084507042253522 1968 2.013422818791946 1969 2.2556390977443606 1970 2.2727272727272725 1971 47.61431411530815 1972 48.861646234676016 1973 45.80965909090909 1974 45.55010511562718 1975 46.19076184763047 1976 44.56906729634002 1977 45.99786552828176 1978 45.84819154355578 1979 46.830357142857146 1980 51.64377861007074 1981 49.58647968356706 1982 49.46935980828483 1983 49.68280467445742 1984 58.42839036755387 1985 59.86903648269409 1986 60.42688203057398 1987 60.660830273933925 1988 63.39572192513369 1989 64.20072426280393 1990 69.56983536909188 1991 68.36871808653589 1992 69.55523672883787 1993 68.08795127024216 1994 68.02052785923755 1995 66.3233779608651 1996 65.84165377584024 1997 66.24846583935634 1998 66.08799363901404 1999 67.99792531120332 2000 66.0342797330891 2001 64.89522847765716 2002 63.786303334528505 2003 66.33210661313706 2004 64.53985076240943 2005 65.3609678698929 2006 64.68707172224761 2007 64.32949869846334 2008 62.95788284653865 2009 63.33925112976114 2010 65.8278439789801 2011 68.41655996585575 2012 66.62185777658287 2013 66.10311673227075 2014 64.90111248454883