Quarter	Percent
1999-04-01	49.6
2000-04-01	50
2001-04-01	50.9
2002-04-01	50.8
2003-04-01	50.7
2004-04-01	50
2005-01-01	51.1
2005-04-01	50.9
2005-07-01	51
2005-10-01	51.4
2006-01-01	51.8
2006-04-01	52.4
2006-07-01	52.7
2006-10-01	53
2007-01-01	52.9
2007-04-01	53.4
2007-07-01	54.1
2007-10-01	54.4
2008-01-01	53.9
2008-04-01	53.9
2008-07-01	54.9
2008-10-01	55.5
2009-01-01	54.5
2009-04-01	55
2009-07-01	55
2009-10-01	56.4
2010-01-01	55.5
2010-04-01	56.0
2010-07-01	56.4
2010-10-01	56.8
2011-01-01	57
2011-04-01	58
2011-07-01	58.4
2011-10-01	58.6
2012-01-01	57.8
2012-04-01	58.4
2012-07-01	58.8
2012-10-01	58.9
2013-01-01	59.1
2013-04-01	59.6
2013-07-01	59.8
2013-10-01	59.7
2014-01-01	59.8
2014-04-01	60.2
2014-07-01	60.4
2014-10-01	60.5
2015-01-01	60.4
2015-04-01	60.7
2015-07-01	60.9
2015-10-01	61.0
2016-01-01	61.4
2016-04-01	61.5
2016-07-01	62.4
2016-10-01	62.7
2017-01-01	62.1
2017-04-01	62.4
2017-07-01	63.0
2017-10-01	63.4
2018-01-01	62.6
2018-04-01	62.6