Year Percent 2006-01-01 23.6 2007-01-01 23.6 2008-01-01 23.6 2009-01-01 23.6 2010-01-01 23.6 2011-01-01 23.6 2012-01-01 23.6 2013-01-01 23.6 2014-01-01 19.0