Year Percent 1995 12.09 1996 12.5 1997 12.77 1998 12.87 1999 13.2 2000 13.18 2001 13.34 2002 13.28 2003 14.95 2004 14.86 2005 15.21 2006 15.52 2007 15.46 2008 15.69 2009 15.22 2010 15.22