Year Percent 1960 79.79187 1961 83.18794 1962 104.2417 1963 94.39164 1964 108.25422 1965 104.68427 1966 107.99335 1967 108.80213 1968 100.06477 1969 101.31554 1970 112.65872 1971 110.96696 1972 114.91505 1973 133.60267 1974 141.28616 1975 125.53041 1976 143.9643 1977 135.36191 1978 137.33192 1979 128.24483 1980 131.50636 1981 115.53258 1982 102.43848 1983 102.14059 1984 96.05431 1985 84.57692 1986 79.78935 1987 70.92928 1988 64.33593 1989 137.98805 1990 374.08949 1991 210.05747 1992 431.76734 1993 529.92519 1994 573.37368 1995 986.64688 1996 743.4128 1997 351.47009 1998 248.88765 1999 223.85695 2000 188.4458 2001 68.4453 2002 65.24862 2003 66.97115 2004 92.81652 2005 80.21818 2006 103.38909 2007 94.66499 2008 124.20585 2009 60.58361 2010 72.08185 2011 91.32263 2012 84.36762 2013 87.79861 2014 121.2618 2015 96.87807 2016 75.25464 2017 69.49027