Quarter	Percent
2000-04-01	50.6
2001-04-01	50.8
2002-04-01	51.5
2003-04-01	53.2
2004-04-01	53.9
2005-01-01	54.6
2005-04-01	55.1
2005-07-01	55.4
2005-10-01	55.8
2006-01-01	55.3
2006-04-01	55.9
2006-07-01	56.6
2006-10-01	56.5
2007-01-01	56.1
2007-04-01	56.9
2007-07-01	57.2
2007-10-01	57.0
2008-01-01	57.0
2008-04-01	57.8
2008-07-01	57.9
2008-10-01	58.1
2009-01-01	57.9
2009-04-01	58.6
2009-07-01	58.5
2009-10-01	58.6
2010-01-01	58.4
2010-04-01	58.8
2010-07-01	58.8
2010-10-01	58.8
2011-01-01	58.8
2011-04-01	59.3
2011-07-01	59.1
2011-10-01	59.7
2012-01-01	59.8
2012-04-01	60.9
2012-07-01	61.4
2012-10-01	61.7
2013-01-01	61.5
2013-04-01	62.3
2013-07-01	63.0
2013-10-01	63.3
2014-01-01	63.2
2014-04-01	63.6
2014-07-01	64.1
2014-10-01	64.6
2015-01-01	64.2
2015-04-01	64.8
2015-07-01	65.4
2015-10-01	65.7
2016-01-01	65.9
2016-04-01	66.5
2016-07-01	66.8
2016-10-01	67.1
2017-01-01	66.8
2017-04-01	67.8
2017-07-01	68.1
2017-10-01	68.5
2018-01-01	68.3
2018-04-01	68.9