Quarter	Percent
2005-01-01	66.0
2005-04-01	66.5
2005-07-01	66.2
2005-10-01	65.6
2006-01-01	65.2
2006-04-01	64.5
2006-07-01	64.7
2006-10-01	63.9
2007-01-01	64.2
2007-04-01	65.5
2007-07-01	66.5
2007-10-01	65.2
2008-01-01	64.8
2008-04-01	66.1
2008-07-01	66.2
2008-10-01	65.9
2009-01-01	65.2
2009-04-01	66.0
2009-07-01	66.3
2009-10-01	65.3
2010-01-01	64.8
2010-04-01	65.4
2010-07-01	66.3
2010-10-01	66.9
2011-01-01	67.2
2011-04-01	67.9
2011-07-01	67.2
2011-10-01	66.8
2012-01-01	66.4
2012-04-01	67.8
2012-07-01	68.5
2012-10-01	67.6
2013-01-01	67.7
2013-04-01	68.5
2013-07-01	68.9
2013-10-01	69.0
2014-01-01	69.5
2014-04-01	69.6
2014-07-01	70.3
2014-10-01	69.5
2015-01-01	69.2
2015-04-01	69.8
2015-07-01	69.7
2015-10-01	70.0
2016-01-01	69.8
2016-04-01	71.6
2016-07-01	71.5
2016-10-01	71.0
2017-01-01	71.2
2017-04-01	71.4
2017-07-01	71.3
2017-10-01	71.3
2018-01-01	71.8
2018-04-01	72.8