Year Percent 2001-01-01 7.25 2002-01-01 8.41 2003-01-01 9.52 2004-01-01 9.91 2005-01-01 10.79 2006-01-01 13.07 2007-01-01 12.26 2008-01-01 10.97 2009-01-01 10.96 2010-01-01 13.62 2011-01-01 12.37 2012-01-01 12.88 2013-01-01 14.68 2014-01-01 13.98 2015-01-01 13.00 2016-01-01 12.75