Year Percent 1995 13.89 1996 13.04 1997 11.54 1998 12.68 1999 13.94 2000 14.88 2001 14.28 2002 14.18 2003 14.02 2004 18.28 2005 18.4 2006 18.06 2007 17.58 2008 17.17 2009 16.66 2010 16.57