Quarter	Percent
1998-04-01	87.9
1999-04-01	87.5
2000-04-01	87.4
2001-04-01	87.9
2002-04-01	88.3
2003-04-01	88.1
2004-04-01	88.2
2005-04-01	88.5
2006-04-01	88.3
2007-04-01	88.9
2008-04-01	89.8
2009-04-01	90
2010-01-01	88.1
2010-04-01	88.4
2010-07-01	88.5
2010-10-01	88.3
2011-01-01	89.0
2011-04-01	89.0
2011-07-01	88.9
2011-10-01	89.2
2012-01-01	89.2
2012-04-01	89.5
2012-07-01	89.6
2012-10-01	89.5
2013-01-01	89.1
2013-04-01	89.0
2013-07-01	89.3
2013-10-01	89.4
2014-01-01	89.5
2014-04-01	89.8
2014-07-01	90.0
2014-10-01	90.4
2015-01-01	90.3
2015-04-01	90.2
2015-07-01	89.9
2015-10-01	90.4
2016-01-01	91.1
2016-04-01	90.4
2016-07-01	90.2
2016-10-01	90.6
2017-01-01	90.6
2017-04-01	90.3
2017-07-01	90.2
2017-10-01	90.4
2018-01-01	90.7
2018-04-01	90.7