Year % 1992 89.94685 1993 90.97737 1994 90.90281 1995 91.4882 1996 93.26458 1997 93.82908 1998 94.79003 1999 95.3653 2000 95.6909 2001 94.8661 2002 95.22784 2003 96.8892 2004 97.7084 2005 98.79159 2006 98.91144 2007 98.88318 2008 98.92066 2009 99.0516 2010 99.20419 2011 99.07929 2012 96.74369 2013 98.15228 2014 98.48564 2015 99.41371 2016 99.54426 2017 99.56388