Year Percent 1995 15.3 1996 15.17 1997 15.01 1998 14.95 1999 15.06 2000 14.71 2001 14.3 2002 15.26 2003 14.78 2004 15.17 2005 14.34 2006 14.45 2007 13.91 2008 13.79 2009 14.65 2010 14.65