Quarter	Percent
2005-01-01	68.8
2005-04-01	69.3
2005-07-01	69.2
2005-10-01	69.5
2006-01-01	69.4
2006-04-01	69.8
2006-07-01	69.8
2006-10-01	70.0
2007-01-01	69.6
2007-04-01	70.1
2007-07-01	69.9
2007-10-01	70.4
2008-01-01	70.1
2008-04-01	70.6
2008-07-01	70.5
2008-10-01	70.8
2009-01-01	70.5
2009-04-01	70.9
2009-07-01	71.0
2009-10-01	71.1
2010-01-01	70.9
2010-04-01	71.3
2010-07-01	71.0
2010-10-01	71.2
2011-01-01	71.0
2011-04-01	71.4
2011-07-01	71.2
2011-10-01	71.5
2012-01-01	71.3
2012-04-01	71.8
2012-07-01	71.6
2012-10-01	71.9
2013-01-01	71.6
2013-04-01	72.0
2013-07-01	71.8
2013-10-01	72.0
2014-01-01	71.9
2014-04-01	72.0
2014-07-01	71.8
2014-10-01	72.2
2015-01-01	71.9
2015-04-01	72.2
2015-07-01	71.9
2015-10-01	72.5
2016-01-01	72.3
2016-04-01	72.6
2016-07-01	72.6
2016-10-01	72.9
2017-01-01	72.7
2017-04-01	73.0