Year Percent 1995 13.05 1996 13.43 1997 13.1 1998 13.55 1999 14.29 2000 15.11 2001 14.39 2002 14.68 2003 14.76 2004 15.14 2005 15.3 2006 15.59 2007 15.59 2008 15.24 2009 16.03 2010 16.03