Year Percent 2001-01-01 7.5 2002-01-01 7.7 2003-01-01 7.7 2004-01-01 7.7 2005-01-01 7.7 2006-01-01 7.7 2007-01-01 7.7 2008-01-01 7.7 2009-01-01 8.5 2010-01-01 8.4 2011-01-01 8.5 2012-01-01 7.8 2013-01-01 5.6 2014-01-01 6.2 2015-01-01 7.8