Quarter	Percent
2000-04-01	53.6
2001-04-01	54.3
2002-04-01	54.5
2003-04-01	55
2004-04-01	55.4
2005-01-01	55.6
2005-04-01	56.1
2005-07-01	56.3
2005-10-01	56.3
2006-01-01	56.4
2006-04-01	57.2
2006-07-01	57.6
2006-10-01	57.5
2007-01-01	57.4
2007-04-01	58.1
2007-07-01	58.6
2007-10-01	58.6
2008-01-01	58.4
2008-04-01	58.9
2008-07-01	59.2
2008-10-01	58.9
2009-01-01	58.2
2009-04-01	58.5
2009-07-01	58.5
2009-10-01	58.3
2010-01-01	57.8
2010-04-01	58.3
2010-07-01	58.5
2010-10-01	58.2
2011-01-01	58
2011-04-01	58.6
2011-07-01	58.6
2011-10-01	58.5
2012-01-01	58.1
2012-04-01	58.7
2012-07-01	58.9
2012-10-01	58.6
2013-01-01	58.2
2013-04-01	58.8
2013-07-01	59.1
2013-10-01	59.0
2014-01-01	58.9
2014-04-01	59.5
2014-07-01	59.9
2014-10-01	59.9
2015-01-01	59.7
2015-04-01	60.4
2015-07-01	60.7
2015-10-01	60.7
2016-01-01	60.6
2016-04-01	61.3
2016-07-01	61.7
2016-10-01	61.7
2017-01-01	61.6
2017-04-01	62.5
2017-07-01	62.8
2017-10-01	62.8
2018-01-01	62.6
2018-04-01	63.4