Quarter	Percent
2005-01-01	64.1
2005-04-01	65.1
2005-07-01	62.9
2005-10-01	64.8
2006-01-01	61.4
2006-04-01	59.4
2006-07-01	60.1
2006-10-01	58.2
2007-01-01	62.2
2007-04-01	63.7
2007-07-01	65.8
2007-10-01	61.4
2008-01-01	61.6
2008-04-01	63.3
2008-07-01	61.7
2008-10-01	65.0
2009-01-01	65.4
2009-04-01	64.7
2009-07-01	63.8
2009-10-01	59.5
2010-01-01	62.2
2010-04-01	64.2
2010-07-01	62.2
2010-10-01	61.8
2011-01-01	63.5
2011-04-01	63.6
2011-07-01	64.9
2011-10-01	65.2
2012-01-01	64.0
2012-04-01	63.5
2012-07-01	66.4
2012-10-01	64.3
2013-01-01	64.1
2013-04-01	63.9
2013-07-01	65.1
2013-10-01	67.8
2014-01-01	68.9
2014-04-01	67.1
2014-07-01	68.6
2014-10-01	68.1
2015-01-01	67.6
2015-04-01	70.8
2015-07-01	70.7
2015-10-01	70.2
2016-01-01	71.7
2016-04-01	75.2
2016-07-01	74.9
2016-10-01	72.6
2017-01-01	72.1
2017-04-01	73.1
2017-07-01	73.0
2017-10-01	75.0
2018-01-01	76.2
2018-04-01	76.4