Year Percent 1995 37.85 1996 40.27 1997 40 1998 40.35 1999 35.62 2000 41.97 2001 42.03 2002 36.31 2003 43.77 2004 45.72 2005 42.28 2006 42.67 2007 43.88 2008 43.7 2009 47.92 2010 52.93