Year Percent 1996-01-01 76.089900000000000 1997-01-01 75.757600000000000 1998-01-01 64.615400000000000 1999-01-01 71.739100000000000 2000-01-01 66.060600000000000 2001-01-01 67.822100000000000 2002-01-01 62.641000000000005 2003-01-01 64.625900000000000 2004-01-01 66.812300000000000 2005-01-01 63.100600000000000 2006-01-01 64.946900000000000 2007-01-01 62.040300000000000 2008-01-01 67.697600000000000 2009-01-01 65.825700000000000 2010-01-01 65.546200000000000 2011-01-01 66.098300000000000 2012-01-01 64.561600000000000 2013-01-01 67.297700000000000 2014-01-01 64.917900000000000