Quarter	Percent
1998-04-01	62.6
1998-10-01	61.9
1999-04-01	61.3
1999-10-01	61.3
2000-04-01	60.0
2000-10-01	60.0
2001-04-01	60.4
2001-10-01	60.5
2002-01-01	59.9
2002-04-01	62.2
2002-07-01	61.9
2002-10-01	62.2
2003-01-01	61.2
2003-04-01	61.5
2003-07-01	63.1
2003-10-01	60.9
2004-01-01	62.0
2004-04-01	62.0
2004-07-01	62.4
2004-10-01	62.4
2005-01-01	61.4
2005-04-01	62.3
2005-07-01	62.3
2005-10-01	62.4
2006-01-01	63.1
2006-04-01	63.8
2006-07-01	65.5
2006-10-01	64.2
2007-01-01	63.9
2007-04-01	65.3
2007-07-01	66.7
2007-10-01	66.5
2008-01-01	66.8
2008-04-01	67.5
2008-07-01	67.4
2008-10-01	67.0
2009-01-01	67.4
2009-04-01	66.7
2009-07-01	64.7
2009-10-01	64.4
2010-01-01	64.5
2010-04-01	64.6
2010-07-01	65.2
2010-10-01	64.1
2011-01-01	63.6
2011-04-01	64.9
2011-07-01	64.6
2011-10-01	64.7
2012-01-01	65.0
2012-04-01	66.4
2012-07-01	66.4
2012-10-01	66.5
2013-01-01	65.9
2013-04-01	65.3
2013-07-01	66.9
2013-10-01	66.1
2014-01-01	66.5
2014-04-01	66.4
2014-07-01	66.4
2014-10-01	66.0
2015-01-01	66.5
2015-04-01	67.5
2015-07-01	68.0
2015-10-01	68.1
2016-01-01	68.0
2016-04-01	68.3
2016-07-01	68.4
2016-10-01	68.0
2017-01-01	68.0
2017-04-01	68.6
2017-07-01	69.5
2017-10-01	69.3
2018-01-01	69.2
2018-04-01	69.7