Quarter	Percent
2005-01-01	68.8
2005-04-01	68.9
2005-07-01	68.6
2005-10-01	68.3
2006-01-01	67.7
2006-04-01	67.7
2006-07-01	68.0
2006-10-01	66.8
2007-01-01	67.5
2007-04-01	68.4
2007-07-01	68.9
2007-10-01	67.1
2008-01-01	67.3
2008-04-01	67.8
2008-07-01	69.4
2008-10-01	69.3
2009-01-01	69.1
2009-04-01	69.8
2009-07-01	70.2
2009-10-01	69.4
2010-01-01	69.1
2010-04-01	69.5
2010-07-01	71.0
2010-10-01	71.4
2011-01-01	71.2
2011-04-01	71.6
2011-07-01	71.6
2011-10-01	71.1
2012-01-01	71.2
2012-04-01	71.9
2012-07-01	72.3
2012-10-01	71.9
2013-01-01	71.9
2013-04-01	72.4
2013-07-01	72.6
2013-10-01	72.7
2014-01-01	73.5
2014-04-01	73.6
2014-07-01	74.1
2014-10-01	73.7
2015-01-01	73.4
2015-04-01	74.1
2015-07-01	74.3
2015-10-01	74.7
2016-01-01	74.7
2016-04-01	75.8
2016-07-01	75.8
2016-10-01	75.6
2017-01-01	75.3
2017-04-01	76.1
2017-07-01	76.1
2017-10-01	76.3
2018-01-01	76.2
2018-04-01	76.8