Year Percent 1998-01-01 12.6 1999-01-01 12.1 2000-01-01 12.8 2001-01-01 12.6 2002-01-01 12.2 2003-01-01 9.6 2004-01-01 10.5 2005-01-01 11.5 2006-01-01 12.3 2007-01-01 10.6 2008-01-01 11.2 2009-01-01 11.7 2010-01-01 12.3 2011-01-01 11.7 2012-01-01 12.3 2013-01-01 13.3 2014-01-01 13.8