Quarter	Percent
2005-01-01	56.4
2005-04-01	56.5
2005-07-01	56.3
2005-10-01	56.0
2006-01-01	55.4
2006-04-01	55.4
2006-07-01	55.5
2006-10-01	54.7
2007-01-01	55.1
2007-04-01	55.8
2007-07-01	56.3
2007-10-01	55.0
2008-01-01	54.9
2008-04-01	55.3
2008-07-01	56.6
2008-10-01	56.5
2009-01-01	56.0
2009-04-01	56.7
2009-07-01	57.0
2009-10-01	56.4
2010-01-01	55.9
2010-04-01	56.3
2010-07-01	57.3
2010-10-01	57.7
2011-01-01	57.3
2011-04-01	57.8
2011-07-01	57.5
2011-10-01	57.0
2012-01-01	57.2
2012-04-01	58.0
2012-07-01	58.2
2012-10-01	57.5
2013-01-01	57.5
2013-04-01	58.1
2013-07-01	58.2
2013-10-01	58.2
2014-01-01	58.8
2014-04-01	58.8
2014-07-01	59.3
2014-10-01	58.8
2015-01-01	58.6
2015-04-01	59.3
2015-07-01	59.3
2015-10-01	59.4
2016-01-01	59.8
2016-04-01	60.6
2016-07-01	60.5
2016-10-01	60.4
2017-01-01	60.3
2017-04-01	60.8
2017-07-01	60.6
2017-10-01	60.6
2018-01-01	60.8
2018-04-01	61.2