Year % 1973 90.24127 1974 97.93039 1975 91.27962 1976 97.01646 1977 94.08898 1979 94.3534 1982 97.75595 1983 97.32213 1984 95.05362 1985 97.26659 1986 96.80363 1987 98.78569 1988 99.49373 1989 98.79721 1990 98.26561 1991 94.02025 1992 96.95369 1993 99.48798 1994 98.72636 1996 98.03728 1999 98.70699 2000 99.94577 2001 98.98802 2002 97.74784 2003 98.47823 2004 99.22658 2005 99.87523 2006 99.63031 2009 97.66702 2010 95.76771 2011 99.42204 2012 98.39354 2013 99.93103