Year Percent 2006-01-01 37.5 2007-01-01 37.5 2008-01-01 37.5 2009-01-01 37.5 2010-01-01 41.9 2011-01-01 41.9 2012-01-01 41.9 2013-01-01 41.9 2014-01-01 41.9 2015-01-01 41.9 2016-01-01 41.9 2017-01-01 46.2