Year Percent 2000 92.03637 2001 92.47559 2002 92.91481 2003 93.35403 2004 93.79325 2005 94.23248 2006 94.6717 2007 95.11092 2008 95.55014 2009 95.98936 2010 96.42858 2011 96.8678 2012 97.30703 2013 97.73957 2014 97.73957 2015 97.73957