Year Percent 1999-01-01 6.450 2000-01-01 5.825 2001-01-01 5.425 2002-01-01 5.800 2003-01-01 6.025 2004-01-01 5.750 2005-01-01 6.175 2006-01-01 6.600 2007-01-01 5.575 2008-01-01 4.200 2009-01-01 5.375 2010-01-01 6.800 2011-01-01 7.950 2012-01-01 9.025 2013-01-01 10.550 2014-01-01 10.425 2015-01-01 10.175 2016-01-01 8.675 2017-01-01 7.450