Quarter	Percent
1998-04-01	70.4
1998-10-01	70.4
1999-04-01	69.7
1999-10-01	69.5
2000-04-01	67.3
2000-10-01	66.3
2001-04-01	66.8
2001-10-01	67.2
2002-01-01	66.6
2002-04-01	68.7
2002-07-01	69.5
2002-10-01	68.5
2003-01-01	68.0
2003-04-01	67.5
2003-07-01	69.7
2003-10-01	66.9
2004-01-01	67.7
2004-04-01	68.5
2004-07-01	68.8
2004-10-01	67.9
2005-01-01	68.4
2005-04-01	68.2
2005-07-01	69.6
2005-10-01	68.2
2006-01-01	70.3
2006-04-01	69.2
2006-07-01	73.1
2006-10-01	70.7
2007-01-01	70.9
2007-04-01	71.9
2007-07-01	74.3
2007-10-01	73.1
2008-01-01	73.0
2008-04-01	73.2
2008-07-01	73.5
2008-10-01	73.2
2009-01-01	72.3
2009-04-01	71.7
2009-07-01	70.2
2009-10-01	68.4
2010-01-01	69.0
2010-04-01	68.5
2010-07-01	69.0
2010-10-01	68.2
2011-01-01	68.5
2011-04-01	69.5
2011-07-01	68.9
2011-10-01	69.7
2012-01-01	69.2
2012-04-01	70.7
2012-07-01	70.9
2012-10-01	71.5
2013-01-01	70.4
2013-04-01	68.8
2013-07-01	71.2
2013-10-01	71.3
2014-01-01	71.0
2014-04-01	70.8
2014-07-01	71.3
2014-10-01	71.7
2015-01-01	71.4
2015-04-01	72.4
2015-07-01	72.5
2015-10-01	73.2
2016-01-01	72.0
2016-04-01	72.3
2016-07-01	72.9
2016-10-01	71.7
2017-01-01	72.3
2017-04-01	72.8
2017-07-01	73.7
2017-10-01	73.8
2018-01-01	73.2
2018-04-01	73.8