Quarter	Percent
1999-04-01	61.6
2000-04-01	61.6
2001-04-01	61.1
2002-04-01	60
2003-04-01	58.7
2004-04-01	57.5
2005-01-01	57.9
2005-04-01	58.5
2005-07-01	59
2005-10-01	59.1
2006-01-01	58.3
2006-04-01	59.2
2006-07-01	60
2006-10-01	60.4
2007-01-01	59.3
2007-04-01	60.5
2007-07-01	61.3
2007-10-01	61.2
2008-01-01	60.5
2008-04-01	60.8
2008-07-01	62.4
2008-10-01	61.9
2009-01-01	60.5
2009-04-01	60.4
2009-07-01	60.9
2009-10-01	61.5
2010-01-01	60.5
2010-04-01	60.9
2010-07-01	61.6
2010-10-01	61.8
2011-01-01	61.5
2011-04-01	62.4
2011-07-01	62.9
2011-10-01	63.2
2012-01-01	62
2012-04-01	62.6
2012-07-01	63.4
2012-10-01	63.1
2013-01-01	61.9
2013-04-01	62.9
2013-07-01	63.1
2013-10-01	63.1
2014-01-01	62.2
2014-04-01	62.6
2014-07-01	63.4
2014-10-01	63.1
2015-01-01	62.1
2015-04-01	62.0
2015-07-01	63.0
2015-10-01	63.2
2016-01-01	63.2
2016-04-01	63.2
2016-07-01	64.0
2016-10-01	64.1
2017-01-01	63.3
2017-04-01	63.6
2017-07-01	64.4
2017-10-01	64.4
2018-01-01	63.8
2018-04-01	63.9