Year Percent 2000-01-01 32.675 2001-01-01 33.900 2002-01-01 34.450 2003-01-01 33.925 2004-01-01 34.200 2005-01-01 35.075 2006-01-01 32.350 2007-01-01 31.650 2008-01-01 31.250 2009-01-01 32.075 2010-01-01 33.050 2011-01-01 31.975 2012-01-01 31.650 2013-01-01 31.600 2014-01-01 31.125 2015-01-01 30.550 2016-01-01 29.425 2017-01-01 28.600