Quarter	Percent
1999-04-01	55.6
2000-01-01	53.7
2000-04-01	54.8
2000-07-01	55.3
2000-10-01	54.4
2001-01-01	54.3
2001-04-01	54.4
2001-07-01	56
2001-10-01	55.8
2002-01-01	54.7
2002-04-01	55.4
2002-07-01	56.2
2002-10-01	55.8
2003-01-01	55.4
2003-04-01	56.5
2003-07-01	58.2
2003-10-01	58.2
2004-01-01	57.2
2004-04-01	57.4
2004-07-01	57.2
2004-10-01	57.4
2005-01-01	57.2
2005-04-01	58.8
2005-07-01	59.2
2005-10-01	59.3
2006-01-01	60.9
2006-04-01	62.6
2006-07-01	62.6
2006-10-01	62.6
2007-01-01	62.3
2007-04-01	63.4
2007-07-01	63.7
2007-10-01	63.1
2008-01-01	63.4
2008-04-01	63.2
2008-07-01	63.6
2008-10-01	63.1
2009-01-01	59.3
2009-04-01	57.3
2009-07-01	57.9
2009-10-01	56.1
2010-01-01	53.8
2010-04-01	54.4
2010-07-01	56.1
2010-10-01	57.6
2011-01-01	57.6
2011-04-01	58.7
2011-07-01	61.1
2011-10-01	59.9
2012-01-01	60.1
2012-04-01	61.1
2012-07-01	62.2
2012-10-01	61.1
2013-01-01	61.3
2013-04-01	63.4
2013-07-01	62.9
2013-10-01	61.9
2014-01-01	61.3
2014-04-01	63.7
2014-07-01	64.2
2014-10-01	64
2015-01-01	63.6
2015-04-01	65.3
2015-07-01	67.4
2015-10-01	65.4
2016-01-01	64.4
2016-04-01	67.2
2016-07-01	66.9
2016-10-01	65.2
2017-01-01	66.6
2017-04-01	67.1
2017-07-01	68.5
2017-10-01	68.7
2018-01-01	66.9
2018-04-01	68.4