Year Percent 2001-01-01 29.950 2002-01-01 30.075 2003-01-01 30.250 2004-01-01 30.475 2005-01-01 29.625 2006-01-01 29.125 2007-01-01 28.800 2008-01-01 28.750 2009-01-01 29.375 2010-01-01 29.475 2011-01-01 29.050 2012-01-01 28.875 2013-01-01 28.500 2014-01-01 28.050 2015-01-01 27.975 2016-01-01 27.900 2017-01-01 27.300