Year % of total 1960 100 1961 100 1962 100 1963 100 1964 100 1965 100 1966 100 1967 100 1968 100 1969 100 1970 100 1971 100 1972 100 1973 100 1974 100 1975 100 1976 100 1977 100 1978 100 1979 100 1980 72.34042553191489 1981 65.8119658119658 1982 67.91044776119404 1983 66.93548387096774 1984 70.07299270072991 1985 79.80295566502463 1986 78.07486631016042 1987 72.10884353741497 1988 82.11920529801326 1989 80.23255813953489 1990 146.68 1991 200.01818181818177 1992 198.6291666666667 1993 209.54285714285717 1994 258.5235 1995 225.60021739130437 1996 103.3744761904762 1997 90.19637096774193 1998 85.75138461538462 1999 103.03753521126762 2000 96.3486274509804 2001 91.87429347826087 2002 92.19391509433962 2003 93.67798319327731 2004 94.2114624505929 2005 81.65010791366907 2006 81.66973890339425 2007 84.78371298405467 2008 85.9848275862069 2009 85.1992340425532 2010 87.41608267716535 2011 86.96238955823293 2012 86.72377637130802 2013 86.34250996015936 2014 81.59241379310345 2015 84.48180300500835 2016 72.73136929460581