Year Percent 2000-01-01 34.825 2001-01-01 36.400 2002-01-01 34.050 2003-01-01 32.250 2004-01-01 31.975 2005-01-01 31.825 2006-01-01 30.700 2007-01-01 29.350 2008-01-01 29.575 2009-01-01 29.375 2010-01-01 29.625 2011-01-01 28.100 2012-01-01 28.350 2013-01-01 27.900 2014-01-01 28.650 2015-01-01 26.950 2016-01-01 28.925 2017-01-01 29.650