Year Percent 2005-01-01 63.7 2006-01-01 64.4 2007-01-01 65.3 2008-01-01 65.7 2009-01-01 64.6 2010-01-01 64.3 2011-01-01 64.6 2012-01-01 65.7 2013-01-01 66.5 2014-01-01 67.6 2015-01-01 68.3 2016-01-01 69.2