Year Percent 2000-01-01 2.350 2001-01-01 1.825 2002-01-01 2.450 2003-01-01 3.500 2004-01-01 4.375 2005-01-01 4.475 2006-01-01 3.575 2007-01-01 2.825 2008-01-01 2.475 2009-01-01 3.400 2010-01-01 4.450 2011-01-01 4.625 2012-01-01 5.525 2013-01-01 7.250 2014-01-01 7.200 2015-01-01 6.575 2016-01-01 5.650 2017-01-01 4.500