Quarter	Percent
1999-04-01	73.6
2000-01-01	74
2000-04-01	75.2
2000-07-01	75.6
2000-10-01	75.9
2001-01-01	75.5
2001-04-01	75.9
2001-07-01	75.9
2001-10-01	76
2002-01-01	75.3
2002-04-01	76.2
2002-07-01	75.8
2002-10-01	75.4
2003-01-01	74.2
2003-04-01	74.5
2003-07-01	74.4
2003-10-01	74.1
2004-01-01	73.3
2004-04-01	73.7
2004-07-01	73.9
2004-10-01	73.4
2005-01-01	72.8
2005-04-01	73.2
2005-07-01	73.6
2005-10-01	73.4
2006-01-01	73.3
2006-04-01	74
2006-07-01	74.5
2006-10-01	74.8
2007-01-01	74.6
2007-04-01	75.2
2007-07-01	75.7
2007-10-01	75.3
2008-01-01	75.2
2008-04-01	76
2008-07-01	76
2008-10-01	76.3
2009-01-01	75.7
2009-04-01	75.6
2009-07-01	75
2009-10-01	74.7
2010-01-01	72.6
2010-04-01	72.8
2010-07-01	72.9
2010-10-01	72.7
2011-01-01	71.5
2011-04-01	71.5
2011-07-01	72.0
2011-10-01	72.0
2012-01-01	71.6
2012-04-01	71.7
2012-07-01	71.7
2012-10-01	71.1
2013-01-01	70.3
2013-04-01	70.3
2013-07-01	70.3
2013-10-01	70.1
2014-01-01	69.5
2014-04-01	70.0
2014-07-01	70.4
2014-10-01	70.4
2015-01-01	70.1
2015-04-01	70.4
2015-07-01	70.7
2015-10-01	70.5
2016-01-01	70.2
2016-04-01	70.6
2016-07-01	71.1
2016-10-01	71.1
2017-01-01	70.8
2017-04-01	71.3
2017-07-01	71.8
2017-10-01	71.9
2018-01-01	71.9
2018-04-01	72.3