Year Percent 1999-01-01 24.575 2000-01-01 23.475 2001-01-01 22.850 2002-01-01 20.950 2003-01-01 20.050 2004-01-01 21.150 2005-01-01 20.600 2006-01-01 19.925 2007-01-01 19.500 2008-01-01 19.075 2009-01-01 17.950 2010-01-01 17.650 2011-01-01 16.775 2012-01-01 16.000 2013-01-01 15.475 2014-01-01 15.450 2015-01-01 15.625 2016-01-01 15.100 2017-01-01 14.950