Quarter	Percent
1999-04-01	51
2000-01-01	49.6
2000-04-01	51.4
2000-07-01	51.2
2000-10-01	50.7
2001-01-01	49.9
2001-04-01	50.3
2001-07-01	53.2
2001-10-01	51.9
2002-01-01	50
2002-04-01	51.8
2002-07-01	52.1
2002-10-01	53.3
2003-01-01	52.6
2003-04-01	52.2
2003-07-01	53.6
2003-10-01	53.9
2004-01-01	54.3
2004-04-01	54.2
2004-07-01	53.4
2004-10-01	53.5
2005-01-01	55.3
2005-04-01	56.8
2005-07-01	55.2
2005-10-01	56
2006-01-01	57.5
2006-04-01	58.8
2006-07-01	57.9
2006-10-01	58.2
2007-01-01	58
2007-04-01	59.4
2007-07-01	59.2
2007-10-01	58.2
2008-01-01	58.2
2008-04-01	58.4
2008-07-01	59.5
2008-10-01	59.1
2009-01-01	57.2
2009-04-01	55.7
2009-07-01	55.1
2009-10-01	54.9
2010-01-01	54.3
2010-04-01	54.3
2010-07-01	53.1
2010-10-01	54
2011-01-01	54.5
2011-04-01	56.2
2011-07-01	57.8
2011-10-01	56.7
2012-01-01	57.6
2012-04-01	58.8
2012-07-01	58.2
2012-10-01	56.9
2013-01-01	57.8
2013-04-01	59.9
2013-07-01	59.1
2013-10-01	58.5
2014-01-01	57.1
2014-04-01	59.5
2014-07-01	60.4
2014-10-01	59.5
2015-01-01	60.1
2015-04-01	61.1
2015-07-01	62.6
2015-10-01	61.6
2016-01-01	61.1
2016-04-01	64.0
2016-07-01	62.2
2016-10-01	61.0
2017-01-01	62.6
2017-04-01	63.2
2017-07-01	64.4
2017-10-01	64.6
2018-01-01	63.3
2018-04-01	64.2