Year Percent 2000-01-01 36.100 2001-01-01 36.650 2002-01-01 37.425 2003-01-01 36.325 2004-01-01 36.200 2005-01-01 36.250 2006-01-01 33.950 2007-01-01 33.800 2008-01-01 33.000 2009-01-01 33.300 2010-01-01 33.375 2011-01-01 32.325 2012-01-01 32.050 2013-01-01 31.700 2014-01-01 31.650 2015-01-01 30.275 2016-01-01 29.275 2017-01-01 28.075