Year Percent 1960 96.56132 1961 87.71139 1962 94.32783 1963 105.22022 1964 90.43806 1965 113.28912 1966 113.99135 1967 140.93915 1968 128.86223 1969 106.27039 1970 116.90621 1971 106.09267 1972 102.80115 1973 92.06009 1974 119.33057 1975 129.29942 1976 140.56662 1977 114.00969 1978 149.0404 1979 161.80299 1980 183.02566 1981 172.34059 1982 158.3032 1983 153.9608 1984 138.93504 1985 139.32943 1986 140.71129 1987 146.88371 1988 142.1931 1989 155.68603 1990 109.35647 1991 113.22139 1992 117.14193 1993 114.42617 1994 120.34157 1995 110.30132 1996 119.66856 1997 118.13363 1998 130.38204 1999 129.53163 2000 112.53662 2001 141.52558 2002 138.52542 2003 143.64223 2004 139.84889 2005 111.07173 2006 108.466 2007 103.18894 2008 95.6257 2009 96.07819 2010 84.70799 2011 80.07468 2012 78.23656 2013 78.66206 2014 84.37886 2015 79.65973 2016 82.33383 2017 82.4221