Quarter	Percent
1999-01-01	65.3
1999-04-01	64
1999-07-01	64
1999-10-01	63.9
2000-01-01	61.5
2000-04-01	61.6
2000-07-01	62.8
2000-10-01	63
2001-01-01	60.9
2001-04-01	61.8
2001-07-01	62.6
2001-10-01	62.8
2002-01-01	61.7
2002-04-01	61.9
2002-07-01	62.7
2002-10-01	63.2
2003-01-01	61.9
2003-04-01	63.5
2003-07-01	64.3
2003-10-01	63.6
2004-01-01	61.6
2004-04-01	62.9
2004-07-01	64.2
2004-10-01	64
2005-01-01	63.1
2005-04-01	64.1
2005-07-01	65.3
2005-10-01	65.9
2006-01-01	65.8
2006-04-01	66.9
2006-07-01	67.5
2006-10-01	67.7
2007-01-01	67.3
2007-04-01	67.9
2007-07-01	68.9
2007-10-01	69.5
2008-01-01	69
2008-04-01	69.2
2008-07-01	70.8
2008-10-01	70.8
2009-01-01	68.7
2009-04-01	68
2009-07-01	67.4
2009-10-01	66.1
2010-01-01	64.3
2010-04-01	65.2
2010-07-01	65.5
2010-10-01	65.7
2011-01-01	65.4
2011-04-01	66.2
2011-07-01	66.6
2011-10-01	66.2
2012-01-01	66.4
2012-04-01	66.7
2012-07-01	67.2
2012-10-01	66.4
2013-01-01	66.6
2013-04-01	66.6
2013-07-01	66.5
2013-10-01	65.8
2014-01-01	66.3
2014-04-01	67.4
2014-07-01	68.3
2014-10-01	68.6
2015-01-01	68.4
2015-04-01	69.4
2015-07-01	69.8
2015-10-01	70.1
2016-01-01	70.5
2016-04-01	71.6
2016-07-01	71.7
2016-10-01	71.7
2017-01-01	71.5
2017-04-01	72.0
2017-07-01	72.1
2017-10-01	72.3
2018-01-01	73.0
2018-04-01	73.6