Year Percent 2000-01-01 9.29 2001-01-01 9.11 2002-01-01 3.49 2003-01-01 4.25 2004-01-01 4.39 2005-01-01 6.92 2006-01-01 6.90 2007-01-01 5.37 2008-01-01 8.08 2009-01-01 8.22 2010-01-01 8.55 2011-01-01 8.57 2012-01-01 8.62 2013-01-01 8.52 2014-01-01 8.29 2015-01-01 7.45 2016-01-01 5.74