Quarter	Percent
1999-01-01	53
1999-04-01	54.2
1999-07-01	52.4
1999-10-01	53.2
2000-01-01	53.9
2000-04-01	55.2
2000-07-01	53.3
2000-10-01	53.7
2001-01-01	54.5
2001-04-01	54.7
2001-07-01	53.6
2001-10-01	55.1
2002-01-01	56.3
2002-04-01	57.2
2002-07-01	56.4
2002-10-01	56.6
2003-01-01	58.3
2003-04-01	59.3
2003-07-01	58.6
2003-10-01	59.5
2004-01-01	60.2
2004-04-01	60.9
2004-07-01	60.5
2004-10-01	61.3
2005-01-01	62.7
2005-04-01	64
2005-07-01	63.5
2005-10-01	63.1
2006-01-01	64.5
2006-04-01	65.1
2006-07-01	64
2006-10-01	64.9
2007-01-01	66
2007-04-01	66.2
2007-07-01	64.5
2007-10-01	64.8
2008-01-01	66.3
2008-04-01	68
2008-07-01	67.7
2008-10-01	68.4
2009-01-01	69.6
2009-04-01	69.9
2009-07-01	67.5
2009-10-01	67.3
2010-01-01	69.4
2010-04-01	69.8
2010-07-01	68.2
2010-10-01	68.3
2011-01-01	69.6
2011-04-01	69.9
2011-07-01	70.4
2011-10-01	69.8
2012-01-01	69.8
2012-04-01	70.6
2012-07-01	68.7
2012-10-01	68.8
2013-01-01	68.5
2013-04-01	69.5
2013-07-01	69.1
2013-10-01	69.8
2014-01-01	69.2
2014-04-01	70.1
2014-07-01	68.4
2014-10-01	68.4
2015-01-01	68.0
2015-04-01	69.5
2015-07-01	67.5
2015-10-01	68.0
2016-01-01	68.5
2016-04-01	69.5
2016-07-01	66.7
2016-10-01	65.7
2017-01-01	66.6
2017-04-01	67.2
2017-07-01	67.1
2017-10-01	66.4
2018-01-01	68.0
2018-04-01	68.0