Year Percent 2000-01-01 14.625 2001-01-01 17.200 2002-01-01 19.475 2003-01-01 19.275 2004-01-01 18.500 2005-01-01 16.850 2006-01-01 13.150 2007-01-01 9.100 2008-01-01 6.500 2009-01-01 7.850 2010-01-01 9.475 2011-01-01 9.150 2012-01-01 9.550 2013-01-01 9.800 2014-01-01 8.625 2015-01-01 7.450 2016-01-01 6.200 2017-01-01 4.975