Quarter	Percent
1999-04-01	54.3
1999-07-01	57.2
1999-10-01	55.4
2000-01-01	55.2
2000-04-01	55.6
2000-07-01	58.1
2000-10-01	56.4
2001-01-01	56.1
2001-04-01	56
2001-07-01	59
2001-10-01	57.2
2002-01-01	57.4
2002-04-01	57.3
2002-07-01	59
2002-10-01	57.4
2003-01-01	57.4
2003-04-01	57.6
2003-07-01	59.7
2003-10-01	58.4
2004-01-01	58.1
2004-04-01	58
2004-07-01	60
2004-10-01	59.7
2005-01-01	59.7
2005-04-01	60.3
2005-07-01	62.1
2005-10-01	61
2006-01-01	61
2006-04-01	61.3
2006-07-01	63.2
2006-10-01	62
2007-01-01	65.4
2007-04-01	66.4
2007-07-01	67.1
2007-10-01	65.9
2008-01-01	65.7
2008-04-01	66.0
2008-07-01	67.0
2008-10-01	65.4
2009-01-01	64.9
2009-04-01	65.6
2009-07-01	66.1
2009-10-01	64.6
2010-01-01	63.8
2010-04-01	65.0
2010-07-01	64.9
2010-10-01	64.4
2011-01-01	63.7
2011-04-01	64.9
2011-07-01	64.8
2011-10-01	64.4
2012-01-01	64.2
2012-04-01	64.7
2012-07-01	64.9
2012-10-01	64.3
2013-01-01	64.4
2013-04-01	65.9
2013-07-01	65.9
2013-10-01	65.1
2014-01-01	64.6
2014-04-01	64.9
2014-07-01	66.0
2014-10-01	65.1
2015-01-01	64.3
2015-04-01	65.3
2015-07-01	65.6
2015-10-01	65.5
2016-01-01	65.1
2016-04-01	66.9
2016-07-01	66.9
2016-10-01	66.2
2017-01-01	66.2
2017-04-01	66.5
2017-07-01	66.9
2017-10-01	66.9
2018-01-01	66.0
2018-04-01	67.4