Quarter	Percent
1998-04-01	76.3
1998-10-01	76.2
1999-04-01	75.2
1999-10-01	74.8
2000-04-01	73.0
2000-10-01	71.7
2001-04-01	72.6
2001-10-01	72.9
2002-01-01	72.2
2002-04-01	74.3
2002-07-01	75.2
2002-10-01	74.0
2003-01-01	73.9
2003-04-01	73.3
2003-07-01	75.6
2003-10-01	72.4
2004-01-01	73.6
2004-04-01	73.8
2004-07-01	74.8
2004-10-01	73.4
2005-01-01	74.1
2005-04-01	73.7
2005-07-01	74.7
2005-10-01	73.4
2006-01-01	74.8
2006-04-01	75.0
2006-07-01	78.0
2006-10-01	76.5
2007-01-01	76.4
2007-04-01	76.9
2007-07-01	79.5
2007-10-01	78.8
2008-01-01	78.0
2008-04-01	77.9
2008-07-01	78.9
2008-10-01	78.4
2009-01-01	77.4
2009-04-01	77.4
2009-07-01	76.8
2009-10-01	75.0
2010-01-01	75.1
2010-04-01	75.1
2010-07-01	75.8
2010-10-01	74.9
2011-01-01	75.2
2011-04-01	76.2
2011-07-01	75.5
2011-10-01	76.4
2012-01-01	75.5
2012-04-01	77.2
2012-07-01	77.6
2012-10-01	77.9
2013-01-01	76.8
2013-04-01	75.0
2013-07-01	77.3
2013-10-01	77.3
2014-01-01	77.7
2014-04-01	77.4
2014-07-01	77.7
2014-10-01	78.2
2015-01-01	77.8
2015-04-01	79.0
2015-07-01	79.1
2015-10-01	79.5
2016-01-01	78.6
2016-04-01	79.0
2016-07-01	79.4
2016-10-01	78.1
2017-01-01	79.0
2017-04-01	79.7
2017-07-01	80.2
2017-10-01	80.3
2018-01-01	79.7
2018-04-01	80.7