Quarter	Percent
1999-04-01	13.6
2000-04-01	11.8
2001-04-01	11.4
2002-04-01	10.6
2003-04-01	12.4
2004-04-01	12.9
2005-01-01	12.3
2005-04-01	13.1
2005-07-01	12.5
2005-10-01	12.2
2006-01-01	13.4
2006-04-01	11.5
2006-07-01	11
2006-10-01	11.8
2007-01-01	10.9
2007-04-01	9.8
2007-07-01	8.9
2007-10-01	9.1
2008-01-01	9.2
2008-04-01	8.3
2008-07-01	7.4
2008-10-01	7.6
2009-01-01	8.8
2009-04-01	7.5
2009-07-01	7.9
2009-10-01	7.7
2010-01-01	8.5
2010-04-01	8.3
2010-07-01	7.5
2010-10-01	7.4
2011-01-01	7.8
2011-04-01	6.7
2011-07-01	6.0
2011-10-01	5.5
2012-01-01	7.0
2012-04-01	6.1
2012-07-01	6.0
2012-10-01	5.6
2013-01-01	6.8
2013-04-01	6.1
2013-07-01	5.6
2013-10-01	5.9
2014-01-01	6.2
2014-04-01	5.6
2014-07-01	4.9
2014-10-01	5.4
2015-01-01	6.0
2015-04-01	5.5
2015-07-01	4.6
2015-10-01	4.9
2016-01-01	4.4
2016-04-01	4.1
2016-07-01	4.0
2016-10-01	4.0
2017-01-01	4.0
2017-04-01	3.6
2017-07-01	3.5
2017-10-01	3.5
2018-01-01	3.7
2018-04-01	3.2