Quarter	Percent
1998-04-01	57.7
1998-10-01	59.1
1999-04-01	57.8
1999-10-01	56.8
2000-04-01	55.2
2000-10-01	54.0
2001-04-01	54.7
2001-10-01	55.5
2002-01-01	55.4
2002-04-01	56.3
2002-07-01	59.6
2002-10-01	57.3
2003-01-01	57.7
2003-04-01	57.0
2003-07-01	58.7
2003-10-01	57.7
2004-01-01	57.0
2004-04-01	58.3
2004-07-01	58.5
2004-10-01	57.7
2005-01-01	58.3
2005-04-01	58.1
2005-07-01	60.2
2005-10-01	59.3
2006-01-01	61.5
2006-04-01	60.8
2006-07-01	65.2
2006-10-01	63.1
2007-01-01	62.1
2007-04-01	63.9
2007-07-01	66.5
2007-10-01	65.7
2008-01-01	64.2
2008-04-01	65.0
2008-07-01	64.4
2008-10-01	61.4
2009-01-01	56.6
2009-04-01	53.9
2009-07-01	52.0
2009-10-01	49.6
2010-01-01	47.8
2010-04-01	49.5
2010-07-01	51.7
2010-10-01	52.1
2011-01-01	51.6
2011-04-01	52.4
2011-07-01	54.0
2011-10-01	54.5
2012-01-01	53.6
2012-04-01	55.0
2012-07-01	57.4
2012-10-01	56.8
2013-01-01	56.4
2013-04-01	56.8
2013-07-01	58.8
2013-10-01	59.1
2014-01-01	57.3
2014-04-01	58.1
2014-07-01	59.2
2014-10-01	59.9
2015-01-01	59.3
2015-04-01	59.7
2015-07-01	60.0
2015-10-01	60.6
2016-01-01	59.6
2016-04-01	60.1
2016-07-01	60.1
2016-10-01	59.4
2017-01-01	59.9
2017-04-01	60.5
2017-07-01	62.1
2017-10-01	62.3
2018-01-01	61.8
2018-04-01	62.1