Quarter	Percent
2005-01-01	53.5
2005-04-01	54.2
2005-07-01	54.4
2005-10-01	54.5
2006-01-01	54.4
2006-04-01	55.2
2006-07-01	55.3
2006-10-01	55.4
2007-01-01	55.2
2007-04-01	55.8
2007-07-01	55.8
2007-10-01	56.0
2008-01-01	55.8
2008-04-01	56.5
2008-07-01	56.3
2008-10-01	56.6
2009-01-01	56.6
2009-04-01	57.2
2009-07-01	56.9
2009-10-01	57.0
2010-01-01	57.1
2010-04-01	57.6
2010-07-01	57.6
2010-10-01	57.3
2011-01-01	57.4
2011-04-01	58.0
2011-07-01	57.9
2011-10-01	58.1
2012-01-01	58.1
2012-04-01	58.9
2012-07-01	58.9
2012-10-01	59.3
2013-01-01	59.2
2013-04-01	59.7
2013-07-01	59.8
2013-10-01	60.0
2014-01-01	59.9
2014-04-01	60.5
2014-07-01	60.6
2014-10-01	60.8
2015-01-01	60.6
2015-04-01	61.1
2015-07-01	61.3
2015-10-01	61.5
2016-01-01	61.6
2016-04-01	62.1
2016-07-01	62.2
2016-10-01	62.4
2017-01-01	62.5
2017-04-01	63.0