Year Percent 2005-01-01 49.9 2006-01-01 49.6 2007-01-01 49.5 2008-01-01 49.2 2009-01-01 49.1 2010-01-01 49.1 2011-01-01 49.1 2012-01-01 48.8 2013-01-01 48.7 2014-01-01 48.7 2015-01-01 48.6 2016-01-01 48.3