Quarter	Percent
1999-04-01	79.4
2000-01-01	75.6
2000-04-01	78.3
2000-07-01	75.2
2000-10-01	75.8
2001-01-01	77.9
2001-04-01	77.7
2001-07-01	76.5
2001-10-01	77.9
2002-01-01	77
2002-04-01	79.3
2002-07-01	79
2002-10-01	75.4
2003-01-01	76.6
2003-04-01	79
2003-07-01	80.5
2003-10-01	80.6
2004-01-01	79.2
2004-04-01	80
2004-07-01	80.2
2004-10-01	79.7
2005-01-01	78.2
2005-04-01	79.7
2005-07-01	83.3
2005-10-01	81.8
2006-01-01	84.6
2006-04-01	87.9
2006-07-01	88.3
2006-10-01	88.6
2007-01-01	89.1
2007-04-01	89.5
2007-07-01	90.4
2007-10-01	89.4
2008-01-01	89.7
2008-04-01	89.2
2008-07-01	87.6
2008-10-01	86.4
2009-01-01	79.4
2009-04-01	77.5
2009-07-01	78.6
2009-10-01	74.1
2010-01-01	69.9
2010-04-01	73.2
2010-07-01	79
2010-10-01	81.2
2011-01-01	80
2011-04-01	80.9
2011-07-01	83.2
2011-10-01	82.1
2012-01-01	81.9
2012-04-01	83.3
2012-07-01	84.5
2012-10-01	82.6
2013-01-01	83.3
2013-04-01	86.2
2013-07-01	84.9
2013-10-01	84.2
2014-01-01	84.2
2014-04-01	86.7
2014-07-01	85.2
2014-10-01	86.4
2015-01-01	84.9
2015-04-01	87.2
2015-07-01	90.5
2015-10-01	88.3
2016-01-01	86.2
2016-04-01	88.5
2016-07-01	89.2
2016-10-01	87.7
2017-01-01	87.4
2017-04-01	87.3
2017-07-01	90.3
2017-10-01	89.0
2018-01-01	87.0
2018-04-01	90.3