Year % 1992 92.92507 1993 93.8966 1994 93.98488 1995 94.12344 1996 95.93679 1997 96.49026 1998 96.94505 1999 97.4771 2000 97.70364 2001 95.96845 2002 95.95122 2003 97.66348 2004 98.67874 2005 99.64777 2006 99.59829 2007 99.47517 2008 99.12882 2009 99.10466 2010 99.20954 2011 99.57704 2012 97.49283 2013 98.60716 2014 98.82052 2015 99.69362 2016 99.4776 2017 99.71808