Year Percent 1995 25.55 1996 20.76 1997 23.51 1998 26.14 1999 29.12 2000 33.46 2001 31.35 2002 25.58 2003 22.4 2004 32.69 2005 29.17 2006 33.98 2007 39.57 2008 41.17 2009 35.06 2010 37.89