Year Percent 1997 96.45658 1998 96.25267 1999 96.81011 2000 96.42308 2001 95.82174 2002 96.15279 2003 96.23818 2004 96.50878 2005 95.97353 2006 96.04665 2007 95.39624 2011 95.66347