Quarter	Percent
1998-01-01	88
1998-04-01	89.1
1998-07-01	89.4
1998-10-01	88.7
1999-01-01	88.3
1999-04-01	88.8
1999-07-01	88.5
1999-10-01	87.3
2000-01-01	87.8
2000-04-01	88.7
2000-07-01	89
2000-10-01	88.6
2001-01-01	88.1
2001-04-01	88.9
2001-07-01	89
2001-10-01	88
2002-01-01	87.6
2002-04-01	89.1
2002-07-01	89.2
2002-10-01	88.8
2003-01-01	88.7
2003-04-01	89.3
2003-07-01	89.8
2003-10-01	89.1
2004-01-01	88.6
2004-04-01	89.6
2004-07-01	89.6
2004-10-01	89.2
2005-01-01	89.1
2005-04-01	89.8
2005-07-01	89.6
2005-10-01	89.4
2006-01-01	89.2
2006-04-01	89.9
2006-07-01	90.5
2006-10-01	90.3
2007-01-01	89.7
2007-04-01	90.1
2007-07-01	90.4
2007-10-01	90.1
2008-01-01	89.9
2008-04-01	90.7
2008-07-01	90.4
2008-10-01	89.5
2009-01-01	88.2
2009-04-01	88.8
2009-07-01	88.8
2009-10-01	87.4
2010-01-01	86.4
2010-04-01	85.9
2010-07-01	85.3
2010-10-01	83.5
2011-01-01	81.4
2011-04-01	81.2
2011-07-01	80.1
2011-10-01	76.9
2012-01-01	75.3
2012-04-01	74.4
2012-07-01	73.7
2012-10-01	72.3
2013-01-01	71
2013-04-01	71.7
2013-07-01	71.8
2013-10-01	71
2014-01-01	70.7
2014-04-01	71.9
2014-07-01	72.7
2014-10-01	71.7
2015-01-01	71.5
2015-04-01	73.8
2015-07-01	75.0
2015-10-01	74.3
2016-01-01	74.6
2016-04-01	76.9
2016-07-01	77.0
2016-10-01	75.5
2017-01-01	75.6
2017-04-01	77.9
2017-07-01	79.0
2017-10-01	77.5
2018-01-01	77.6
2018-04-01	79.9