Year Percent 1999 96.15715 2000 96.77807 2001 96.62639 2002 97.36528 2003 97.37373 2004 97.11299 2005 97.18932 2006 97.33034 2007 98.09794 2008 97.89517 2009 98.2226 2010 94.36051