Quarter	Percent
1999-04-01	62.9
2000-04-01	63
2001-04-01	63.7
2002-04-01	64.2
2003-04-01	65
2004-04-01	65.1
2005-01-01	66.7
2005-04-01	66.7
2005-07-01	67
2005-10-01	67.3
2006-01-01	68.1
2006-04-01	68.2
2006-07-01	68.7
2006-10-01	69
2007-01-01	69
2007-04-01	69
2007-07-01	69.6
2007-10-01	69.8
2008-01-01	69.4
2008-04-01	69.4
2008-07-01	69.9
2008-10-01	70.1
2009-01-01	69.8
2009-04-01	70.3
2009-07-01	70.3
2009-10-01	71.1
2010-01-01	70.7
2010-04-01	70.7
2010-07-01	70.9
2010-10-01	71.3
2011-01-01	71.3
2011-04-01	71.8
2011-07-01	72.2
2011-10-01	72.3
2012-01-01	71.3
2012-04-01	71.8
2012-07-01	72
2012-10-01	72.3
2013-01-01	72.4
2013-04-01	72.5
2013-07-01	72.8
2013-10-01	72.8
2014-01-01	72.6
2014-04-01	72.8
2014-07-01	73.1
2014-10-01	73
2015-01-01	73.0
2015-04-01	73.0
2015-07-01	72.9
2015-10-01	73.3
2016-01-01	73.3
2016-04-01	73.1
2016-07-01	74.0
2016-10-01	74.1
2017-01-01	73.7
2017-04-01	73.4
2017-07-01	74.2
2017-10-01	74.6
2018-01-01	74.0
2018-04-01	73.8