Year Percent 2000-01-01 30.050 2001-01-01 31.075 2002-01-01 31.800 2003-01-01 31.000 2004-01-01 31.100 2005-01-01 31.950 2006-01-01 28.875 2007-01-01 28.025 2008-01-01 27.425 2009-01-01 28.200 2010-01-01 29.125 2011-01-01 27.875 2012-01-01 27.325 2013-01-01 27.100 2014-01-01 26.350 2015-01-01 25.550 2016-01-01 24.275 2017-01-01 23.125