Year % (national estimate) 1990 55.36 1991 53.33 1996 52.39 1998 55.01 1999 57.14 2000 58.81 2001 51.3 2002 50 2003 58.5 2004 59.58 2005 60.53 2006 58.88 2007 57.97 2009 47.56 2010 68.09 2012 72.947 2013 71.72 2014 62.034