Quarter	Percent
1999-04-01	54.6
1999-07-01	57
1999-10-01	55.9
2000-01-01	55.9
2000-04-01	56.4
2000-07-01	58.4
2000-10-01	57
2001-01-01	56.9
2001-04-01	57
2001-07-01	58.9
2001-10-01	57.5
2002-01-01	57.1
2002-04-01	57.1
2002-07-01	58.3
2002-10-01	57
2003-01-01	56.8
2003-04-01	57
2003-07-01	58.1
2003-10-01	57.5
2004-01-01	57.5
2004-04-01	57.4
2004-07-01	58.8
2004-10-01	58.4
2005-01-01	58.5
2005-04-01	58.9
2005-07-01	60.3
2005-10-01	59.4
2006-01-01	59.7
2006-04-01	60
2006-07-01	61.2
2006-10-01	60.6
2007-01-01	63.0
2007-04-01	63.3
2007-07-01	64.0
2007-10-01	63.0
2008-01-01	62.3
2008-04-01	62.1
2008-07-01	61.7
2008-10-01	59.8
2009-01-01	57.2
2009-04-01	56.4
2009-07-01	55.8
2009-10-01	54.7
2010-01-01	53.8
2010-04-01	53.9
2010-07-01	53.6
2010-10-01	52.7
2011-01-01	52.2
2011-04-01	52.8
2011-07-01	52.4
2011-10-01	52.4
2012-01-01	51.7
2012-04-01	52.1
2012-07-01	52.3
2012-10-01	52.4
2013-01-01	52.3
2013-04-01	53.2
2013-07-01	54.1
2013-10-01	54.2
2014-01-01	53.6
2014-04-01	54.0
2014-07-01	54.9
2014-10-01	55.2
2015-01-01	54.8
2015-04-01	55.6
2015-07-01	56.2
2015-10-01	56.2
2016-01-01	55.9
2016-04-01	57.0
2016-07-01	57.6
2016-10-01	57.5
2017-01-01	57.2
2017-04-01	57.6
2017-07-01	58.1
2017-10-01	58.4
2018-01-01	58.1
2018-04-01	58.6