Year Percent 1995 34.51 1996 32.61 1997 33.04 1998 35.02 1999 35.16 2000 30.95 2001 31.46 2002 30.48 2003 32.07 2004 27.4 2005 26.4 2006 32.9 2007 39.98 2008 33.96 2009 37.54 2010 37.84