Quarter	Percent
1999-04-01	64.8
2000-04-01	65.3
2001-04-01	65.7
2002-04-01	65.4
2003-04-01	64.9
2004-04-01	64.3
2005-01-01	64.9
2005-04-01	65.3
2005-07-01	65.7
2005-10-01	65.9
2006-01-01	66
2006-04-01	67
2006-07-01	67.7
2006-10-01	67.9
2007-01-01	68.1
2007-04-01	68.7
2007-07-01	69.5
2007-10-01	69.6
2008-01-01	69.4
2008-04-01	69.7
2008-07-01	70.6
2008-10-01	70.7
2009-01-01	69.7
2009-04-01	70.2
2009-07-01	70.3
2009-10-01	71.1
2010-01-01	70.4
2010-04-01	71.1
2010-07-01	71.6
2010-10-01	71.9
2011-01-01	71.7
2011-04-01	72.6
2011-07-01	73
2011-10-01	73.5
2012-01-01	72.3
2012-04-01	72.9
2012-07-01	73.3
2012-10-01	73.5
2013-01-01	72.8
2013-04-01	73.5
2013-07-01	73.8
2013-10-01	73.9
2014-01-01	73.2
2014-04-01	73.6
2014-07-01	74.2
2014-10-01	74.1
2015-01-01	73.7
2015-04-01	73.6
2015-07-01	74.2
2015-10-01	74.4
2016-01-01	74.0
2016-04-01	74.2
2016-07-01	75.1
2016-10-01	75.3
2017-01-01	74.6
2017-04-01	74.8
2017-07-01	75.6
2017-10-01	76.0
2018-01-01	75.4
2018-04-01	75.4