Year Percent 2005-01-01 46.5 2006-01-01 46.4 2007-01-01 46.8 2008-01-01 46.9 2009-01-01 48.4 2010-01-01 49.1 2011-01-01 49.1 2012-01-01 49.2 2013-01-01 49.4 2014-01-01 49.4 2015-01-01 49.6 2016-01-01 49.5