Year % 1975 93.42105 1977 92.06642 1978 97.0696 1982 91.75868 1983 91.72584 1984 93.1418 1985 92.49358 1986 95.07296 1987 93.66259 1988 94.76985 1989 95.50774 1991 96.72653 1993 97.90486 1994 98.79032 1995 98.49732 1996 98.96578 1999 98.9925 2000 99.81262 2001 98.99147 2002 98.56667 2011 100 2012 100 2013 99.80737 2014 99.64189 2015 98.83381 2016 98.82031 2017 100