Year Percent 1999-01-01 7.350 2000-01-01 6.600 2001-01-01 5.750 2002-01-01 6.000 2003-01-01 6.450 2004-01-01 6.025 2005-01-01 6.225 2006-01-01 5.000 2007-01-01 4.100 2008-01-01 4.050 2009-01-01 6.025 2010-01-01 7.600 2011-01-01 8.350 2012-01-01 8.525 2013-01-01 9.625 2014-01-01 9.150 2015-01-01 8.175 2016-01-01 7.575 2017-01-01 5.900