Year Percent 1995-01-01 66.6371159825000 1996-01-01 67.2903418100000 1997-01-01 67.4625178075000 1998-01-01 66.0065515150000 1999-01-01 65.0318857400000 2000-01-01 62.2909788300000 2001-01-01 60.7316753400000 2002-01-01 59.3278379300000 2003-01-01 56.7380447950000 2004-01-01 55.7114891025000 2005-01-01 54.3391172075000 2006-01-01 51.7532245700000 2007-01-01 49.7244990200000 2008-01-01 48.4631489650000 2009-01-01 47.0242801225000 2010-01-01 46.0239510150000 2011-01-01 45.3745314000000 2012-01-01 42.4083333333333 2013-01-01 40.8333333333333 2014-01-01 39.7333333333333 2015-01-01 38.2166666666667 2016-01-01 38.2083333333333 2017-01-01 38.6416666666667