Quarter	Percent
2005-01-01	72.2
2005-04-01	73.0
2005-07-01	72.5
2005-10-01	71.8
2006-01-01	71.2
2006-04-01	70.7
2006-07-01	71.0
2006-10-01	69.9
2007-01-01	70.1
2007-04-01	71.5
2007-07-01	72.5
2007-10-01	71.0
2008-01-01	70.5
2008-04-01	71.8
2008-07-01	72.0
2008-10-01	72.0
2009-01-01	71.5
2009-04-01	72.2
2009-07-01	72.2
2009-10-01	71.0
2010-01-01	70.9
2010-04-01	71.4
2010-07-01	72.4
2010-10-01	73.1
2011-01-01	73.6
2011-04-01	73.9
2011-07-01	73.5
2011-10-01	73.2
2012-01-01	72.5
2012-04-01	73.7
2012-07-01	74.5
2012-10-01	74.0
2013-01-01	73.9
2013-04-01	74.5
2013-07-01	75.1
2013-10-01	75.3
2014-01-01	75.7
2014-04-01	75.7
2014-07-01	76.6
2014-10-01	75.9
2015-01-01	75.4
2015-04-01	75.8
2015-07-01	75.9
2015-10-01	76.3
2016-01-01	76.1
2016-04-01	77.7
2016-07-01	77.6
2016-10-01	77.2
2017-01-01	77.2
2017-04-01	77.4
2017-07-01	77.4
2017-10-01	77.6
2018-01-01	78.0
2018-04-01	78.9