Quarter	Percent
2005-01-01	64.9
2005-04-01	65.6
2005-07-01	65.7
2005-10-01	65.7
2006-01-01	65.6
2006-04-01	66.4
2006-07-01	66.2
2006-10-01	66.3
2007-01-01	66.2
2007-04-01	66.8
2007-07-01	66.8
2007-10-01	66.8
2008-01-01	66.8
2008-04-01	67.3
2008-07-01	67.1
2008-10-01	67.3
2009-01-01	67.3
2009-04-01	67.6
2009-07-01	67.3
2009-10-01	67.3
2010-01-01	67.4
2010-04-01	67.8
2010-07-01	67.5
2010-10-01	67.3
2011-01-01	67.3
2011-04-01	67.8
2011-07-01	67.6
2011-10-01	68.0
2012-01-01	67.8
2012-04-01	68.5
2012-07-01	68.7
2012-10-01	69.2
2013-01-01	68.8
2013-04-01	69.2
2013-07-01	69.4
2013-10-01	69.6
2014-01-01	69.4
2014-04-01	70.0
2014-07-01	70.2
2014-10-01	70.4
2015-01-01	70.1
2015-04-01	70.6
2015-07-01	70.6
2015-10-01	70.7
2016-01-01	70.9
2016-04-01	71.4
2016-07-01	71.6
2016-10-01	71.8
2017-01-01	71.6
2017-04-01	72.2