Year Percent 2005-01-01 43.4 2006-01-01 44.6 2007-01-01 45.4 2008-01-01 46.0 2009-01-01 47.1 2010-01-01 47.9 2011-01-01 48.6 2012-01-01 49.6 2013-01-01 50.6 2014-01-01 51.5 2015-01-01 52.3 2016-01-01 53.3