Quarter	Percent
1999-04-01	8.7
2000-04-01	7.6
2001-04-01	7.4
2002-04-01	7.9
2003-04-01	9.1
2004-04-01	9.8
2005-01-01	10.4
2005-04-01	10.3
2005-07-01	9.9
2005-10-01	10.1
2006-01-01	10.3
2006-04-01	9.3
2006-07-01	9.0
2006-10-01	9.3
2007-01-01	8.6
2007-04-01	8.2
2007-07-01	7.9
2007-10-01	7.8
2008-01-01	7.8
2008-04-01	7.5
2008-07-01	6.9
2008-10-01	6.5
2009-01-01	7.3
2009-04-01	6.9
2009-07-01	7.0
2009-10-01	6.4
2010-01-01	6.8
2010-04-01	6.1
2010-07-01	5.8
2010-10-01	5.8
2011-01-01	5.6
2011-04-01	5.0
2011-07-01	5.1
2011-10-01	5.0
2012-01-01	5.2
2012-04-01	4.9
2012-07-01	4.7
2012-10-01	4.8
2013-01-01	4.9
2013-04-01	4.6
2013-07-01	4.4
2013-10-01	4.6
2014-01-01	4.7
2014-04-01	4.2
2014-07-01	4.2
2014-10-01	4.4
2015-01-01	4.1
2015-04-01	4.2
2015-07-01	3.6
2015-10-01	4.2
2016-01-01	4.1
2016-04-01	3.6
2016-07-01	3.4
2016-10-01	3.1
2017-01-01	3.4
2017-04-01	3.0
2017-07-01	3.1
2017-10-01	3.0
2018-01-01	2.8
2018-04-01	2.8