Year % 1992 93.65661 1993 94.48271 1994 94.28814 1995 94.66642 1996 96.39231 1997 96.64946 1998 97.2847 1999 97.7636 2000 97.96159 2001 96.3867 2002 96.36998 2003 97.93911 2004 98.85621 2005 99.73209 2006 99.68114 2007 99.54614 2008 99.20559 2009 99.18236 2010 99.27007 2011 99.61137 2012 97.68857 2013 98.71079 2014 98.90338 2015 99.70943 2016 99.50903 2017 99.73263