Quarter	Percent
1998-04-01	70.8
1999-04-01	72.1
2000-04-01	72.6
2001-01-01	74.8
2001-04-01	76.1
2001-07-01	76.9
2001-10-01	75.1
2002-01-01	74
2002-04-01	75.5
2002-07-01	76
2002-10-01	74.3
2003-01-01	73
2003-04-01	74.9
2003-07-01	75.6
2003-10-01	73.5
2004-01-01	72.4
2004-04-01	74
2004-07-01	74.9
2004-10-01	73.1
2005-01-01	72.4
2005-04-01	74.6
2005-07-01	75.8
2005-10-01	74.4
2006-01-01	73.8
2006-04-01	75.5
2006-07-01	77
2006-10-01	75.6
2007-01-01	75.1
2007-04-01	76.7
2007-07-01	78.1
2007-10-01	76.3
2008-01-01	75.8
2008-04-01	77.2
2008-07-01	78.2
2008-10-01	75.8
2009-01-01	73.8
2009-04-01	74.5
2009-07-01	75
2009-10-01	73.4
2010-01-01	72.5
2010-04-01	74.8
2010-07-01	76.1
2010-10-01	74.8
2011-01-01	74.3
2011-04-01	76.2
2011-07-01	77.2
2011-10-01	75.4
2012-01-01	74.1
2012-04-01	76
2012-07-01	76.9
2012-10-01	75.5
2013-01-01	74.8
2013-04-01	76.3
2013-07-01	77.9
2013-10-01	76.2
2014-01-01	75.1
2014-04-01	76.7
2014-07-01	78
2014-10-01	76.4
2015-01-01	75.6
2015-04-01	77.1
2015-07-01	78.2
2015-10-01	77.1
2016-01-01	76.1
2016-04-01	77.9
2016-07-01	78.8
2016-10-01	77.3
2017-01-01	76.8
2017-04-01	78.5
2017-07-01	79.6
2017-10-01	78.1
2018-01-01	77.7
2018-04-01	79.0