Year Percent 2000-01-01 57.675 2001-01-01 56.550 2002-01-01 56.825 2003-01-01 55.150 2004-01-01 54.575 2005-01-01 53.425 2006-01-01 52.425 2007-01-01 54.450 2008-01-01 57.325 2009-01-01 52.575 2010-01-01 51.450 2011-01-01 50.825 2012-01-01 52.200 2013-01-01 51.800 2014-01-01 50.150 2015-01-01 50.375 2016-01-01 48.475 2017-01-01 48.200