Quarter	Percent
2000-04-01	51.3
2001-04-01	52.3
2002-04-01	53.1
2003-04-01	54.0
2004-04-01	54.4
2005-01-01	55.1
2005-04-01	55.6
2005-07-01	55.6
2005-10-01	55.8
2006-01-01	56.0
2006-04-01	56.7
2006-07-01	57.0
2006-10-01	57.1
2007-01-01	57.1
2007-04-01	57.8
2007-07-01	58.3
2007-10-01	58.3
2008-01-01	58.2
2008-04-01	58.6
2008-07-01	58.9
2008-10-01	58.7
2009-01-01	58.0
2009-04-01	58.3
2009-07-01	58.1
2009-10-01	58.1
2010-01-01	57.7
2010-04-01	58
2010-07-01	58.1
2010-10-01	58.1
2011-01-01	57.8
2011-04-01	58.5
2011-07-01	58.4
2011-10-01	58.3
2012-01-01	57.9
2012-04-01	58.4
2012-07-01	58.4
2012-10-01	58.2
2013-01-01	57.8
2013-04-01	58.3
2013-07-01	58.5
2013-10-01	58.4
2014-01-01	58.2
2014-04-01	58.8
2014-07-01	58.9
2014-10-01	59.0
2015-01-01	58.8
2015-04-01	59.5
2015-07-01	59.6
2015-10-01	59.7
2016-01-01	59.7
2016-04-01	60.3
2016-07-01	60.7
2016-10-01	60.7
2017-01-01	60.5
2017-04-01	61.2
2017-07-01	61.5
2017-10-01	61.7
2018-01-01	61.4
2018-04-01	62.1