Quarter	Percent
1999-01-01	62.2
2000-01-01	62.5
2001-01-01	62.3
2002-01-01	62.6
2003-01-01	64.2
2003-04-01	64.0
2003-07-01	63.9
2003-10-01	63.8
2004-01-01	64.0
2004-04-01	64.1
2004-07-01	64.5
2004-10-01	64.4
2005-01-01	64.3
2005-04-01	64.5
2005-07-01	64.6
2005-10-01	64.3
2006-01-01	64.4
2006-04-01	64.1
2006-07-01	64.8
2006-10-01	64.7
2007-01-01	64.6
2007-04-01	64.8
2007-07-01	65.1
2007-10-01	65.1
2008-01-01	64.9
2008-04-01	65.1
2008-07-01	65.3
2008-10-01	65.4
2009-01-01	65.4
2009-04-01	65.9
2009-07-01	65.9
2009-10-01	65.6
2010-01-01	65.8
2010-04-01	65.8
2010-07-01	66.0
2010-10-01	65.6
2011-01-01	65.5
2011-04-01	65.6
2011-07-01	65.8
2011-10-01	66.0
2012-01-01	65.9
2012-04-01	66.3
2012-07-01	66.4
2012-10-01	66.7
2013-01-01	66.5
2013-04-01	66.8
2013-07-01	67.2
2013-10-01	67.3
2014-01-01	67.0
2014-04-01	67.0
2014-07-01	67.1
2014-10-01	67.3
2015-01-01	67.0
2015-04-01	67.2
2015-07-01	67.6
2015-10-01	67.5
2016-01-01	67.6
2016-04-01	67.4
2016-07-01	67.9
2016-10-01	67.6
2017-01-01	67.3
2017-04-01	67.7
2017-07-01	67.6
2017-10-01	67.7
2018-01-01	68.0
2018-04-01	68.1