Year Percent 1997-01-01 10.350 1998-01-01 9.900 1999-01-01 12.500 2000-01-01 15.850 2001-01-01 13.750 2002-01-01 12.325 2003-01-01 10.800 2004-01-01 11.100 2005-01-01 9.175 2006-01-01 6.250 2007-01-01 5.400 2008-01-01 5.750 2009-01-01 16.700 2010-01-01 19.275 2011-01-01 13.075 2012-01-01 10.925 2013-01-01 9.075 2014-01-01 7.850 2015-01-01 6.275 2016-01-01 7.425 2017-01-01 6.175