Year Percent 2000-01-01 4.500 2001-01-01 4.100 2002-01-01 4.825 2003-01-01 5.125 2004-01-01 4.975 2005-01-01 4.675 2006-01-01 4.650 2007-01-01 5.125 2008-01-01 7.800 2009-01-01 15.475 2010-01-01 17.500 2011-01-01 18.175 2012-01-01 18.175 2013-01-01 15.275 2014-01-01 13.050 2015-01-01 11.100 2016-01-01 9.300 2017-01-01 7.300