Year Percent 1995 33.1 1996 31.5 1997 32.41 1998 32.87 1999 33.38 2000 32.98 2001 31.79 2002 31.56 2003 31.62 2004 31.86 2005 30.63 2006 30.79 2007 30.57 2008 30.5 2009 30.49 2010 30.87