Year Percent 1996-01-01 63.711600000000000 1997-01-01 67.154400000000000 1998-01-01 62.501800000000000 1999-01-01 67.378200000000000 2000-01-01 66.053400000000000 2001-01-01 69.777400000000000 2002-01-01 67.793300000000000 2003-01-01 64.523300000000000 2004-01-01 63.027200000000000 2005-01-01 68.294900000000000 2006-01-01 56.926400000000000 2007-01-01 64.385700000000000 2008-01-01 60.176900000000000 2009-01-01 68.232400000000000 2010-01-01 59.623000000000005 2011-01-01 59.426400000000000 2012-01-01 67.651700000000000 2013-01-01 57.256600000000000 2014-01-01 60.961800000000000