Quarter	Percent
1998-04-01	55.9
1998-10-01	54.6
1999-04-01	54.1
1999-10-01	54.3
2000-04-01	53.6
2000-10-01	54.5
2001-04-01	55.0
2001-10-01	54.7
2002-01-01	54.2
2002-04-01	56.7
2002-07-01	55.3
2002-10-01	56.8
2003-01-01	55.3
2003-04-01	56.3
2003-07-01	57.5
2003-10-01	55.8
2004-01-01	57.1
2004-04-01	56.4
2004-07-01	56.9
2004-10-01	57.7
2005-01-01	55.3
2005-04-01	57.1
2005-07-01	56.1
2005-10-01	57.4
2006-01-01	56.9
2006-04-01	59.2
2006-07-01	59.0
2006-10-01	58.6
2007-01-01	57.9
2007-04-01	59.6
2007-07-01	60.2
2007-10-01	60.7
2008-01-01	61.3
2008-04-01	62.6
2008-07-01	62.0
2008-10-01	61.6
2009-01-01	63.2
2009-04-01	62.3
2009-07-01	59.9
2009-10-01	60.9
2010-01-01	60.6
2010-04-01	61.3
2010-07-01	61.9
2010-10-01	60.6
2011-01-01	59.4
2011-04-01	61.0
2011-07-01	60.9
2011-10-01	60.4
2012-01-01	61.4
2012-04-01	62.6
2012-07-01	62.6
2012-10-01	62.2
2013-01-01	61.9
2013-04-01	62.3
2013-07-01	63.1
2013-10-01	61.5
2014-01-01	62.6
2014-04-01	62.6
2014-07-01	62.1
2014-10-01	61.0
2015-01-01	62.2
2015-04-01	63.1
2015-07-01	64.0
2015-10-01	63.7
2016-01-01	64.4
2016-04-01	64.8
2016-07-01	64.3
2016-10-01	64.8
2017-01-01	64.2
2017-04-01	64.9
2017-07-01	65.8
2017-10-01	65.4
2018-01-01	65.6
2018-04-01	66.1