Year Percent 1995 49.5 1996 53.41 1997 55.76 1998 58.19 1999 59.11 2000 61.72 2001 64.43 2002 64.17 2003 63.77 2004 62.03 2005 61.23 2006 59.35 2007 53.07 2008 50.05 2009 47.5 2010 46.4