Year Percent 1995-01-01 68.9832942325000 1996-01-01 67.9516757350000 1997-01-01 65.3912880500000 1998-01-01 64.6784188750000 1999-01-01 65.2643610575000 2000-01-01 63.8826726400000 2001-01-01 65.2174184250000 2002-01-01 65.8417810525000 2003-01-01 65.8377058925000 2004-01-01 68.3937413900000 2005-01-01 68.4598206900000 2006-01-01 70.1096598275000 2007-01-01 71.3979799850000 2008-01-01 71.7380645800000 2009-01-01 72.0794991025000 2010-01-01 72.5411824675000 2011-01-01 74.1178340700000 2012-01-01 75.5000000000000 2013-01-01 76.7083333333334 2014-01-01 76.1500000000000 2015-01-01 76.5583333333334 2016-01-01 76.7833333333333 2017-01-01 77.3500000000000