Quarter	Percent
2005-01-01	49.5
2005-04-01	50.1
2005-07-01	50.4
2005-10-01	50.3
2006-01-01	49.9
2006-04-01	50.4
2006-07-01	50.7
2006-10-01	50.6
2007-01-01	50.1
2007-04-01	50.6
2007-07-01	50.7
2007-10-01	50.8
2008-01-01	50.3
2008-04-01	51.0
2008-07-01	51.0
2008-10-01	50.9
2009-01-01	50.5
2009-04-01	51.0
2009-07-01	51.2
2009-10-01	50.9
2010-01-01	50.6
2010-04-01	51.1
2010-07-01	51.1
2010-10-01	50.8
2011-01-01	50.5
2011-04-01	51.1
2011-07-01	51.1
2011-10-01	51.1
2012-01-01	50.7
2012-04-01	51.4
2012-07-01	51.4
2012-10-01	51.3
2013-01-01	50.9
2013-04-01	51.5
2013-07-01	51.4
2013-10-01	51.4
2014-01-01	51.0
2014-04-01	51.4
2014-07-01	51.4
2014-10-01	51.4
2015-01-01	51.0
2015-04-01	51.5
2015-07-01	51.4
2015-10-01	51.6
2016-01-01	51.4
2016-04-01	51.7
2016-07-01	51.9
2016-10-01	51.7
2017-01-01	51.6
2017-04-01	52.0