Year Percent 1995-01-01 67 1996-01-01 70 1997-01-01 64 1998-01-01 64 1999-01-01 64 2000-01-01 64 2001-01-01 75 2002-01-01 75 2003-01-01 69 2004-01-01 69 2005-01-01 69 2006-01-01 71 2007-01-01 71 2008-01-01 73 2009-01-01 71 2010-01-01 71 2011-01-01 71 2012-01-01 71 2013-01-01 71