Year Percent 2006-01-01 20.9000 2007-01-01 16.5000 2008-01-01 24.4000 2009-01-01 22.0000 2010-01-01 18.9027 2011-01-01 19.2639 2012-01-01 20.4935 2013-01-01 19.2821 2014-01-01 13.8224 2015-01-01 12.8676