Year Percent 1995 15.21 1996 15.65 1997 15.46 1998 15.45 1999 15.15 2000 15.31 2001 16.05 2002 16.2 2003 16.45 2004 15.98 2005 15.73 2006 15.85 2007 15.43 2008 14.67 2009 14.46 2010 14.56