Year Percent 1995 25.68 1996 27.12 1997 25.05 1998 20.13 1999 19.04 2000 21.25 2001 20.48 2002 28.17 2003 23.33 2004 24.67 2005 25.56 2006 29.99 2007 30.68 2008 33.48 2009 34.84 2010 38.48