Year % 1972 84.03177 1974 92.36984 1975 77.68541 1976 69.92464 1977 86.56856 1978 94.10618 1979 92.42954 1980 95.75422 1981 92.51496 1982 99.56201 1983 85.79985 1991 90.5911 1992 95.65064 1993 96.57904 2002 90.17261 2003 97.88996 2004 96.9837 2005 99.38296 2006 99.18352 2007 99.66443 2008 99.49258 2009 99.62595 2010 99.94546 2011 99.60396 2012 99.74107 2013 99.72625 2014 99.38369 2016 99.73679 2017 99.80164