Quarter	Percent
1999-04-01	4.2
1999-07-01	3.7
1999-10-01	3.6
2000-01-01	3.1
2000-04-01	2.6
2000-07-01	2.6
2000-10-01	2.5
2001-01-01	2.8
2001-04-01	2.6
2001-07-01	2.7
2001-10-01	2.4
2002-01-01	2.9
2002-04-01	2.4
2002-07-01	2.2
2002-10-01	2.5
2003-01-01	2.7
2003-04-01	2.6
2003-07-01	2.5
2003-10-01	2.8
2004-01-01	2.7
2004-04-01	2.9
2004-07-01	2.7
2004-10-01	2.8
2005-01-01	3.1
2005-04-01	3.0
2005-07-01	3.1
2005-10-01	2.8
2006-01-01	2.1
2006-04-01	2.6
2006-07-01	2.7
2006-10-01	2.3
2007-01-01	2.7
2007-04-01	2.3
2007-07-01	2.4
2007-10-01	2.3
2008-01-01	3.1
2008-04-01	3.4
2008-07-01	3.7
2008-10-01	4.3
2009-01-01	6.7
2009-04-01	7.2
2009-07-01	7.9
2009-10-01	8.4
2010-01-01	9.1
2010-04-01	9.8
2010-07-01	10.2
2010-10-01	11.4
2011-01-01	10.9
2011-04-01	10.8
2011-07-01	11.3
2011-10-01	12.6
2012-01-01	12.7
2012-04-01	12.6
2012-07-01	13.1
2012-10-01	12.4
2013-01-01	12.2
2013-04-01	11.7
2013-07-01	11.8
2013-10-01	11.8
2014-01-01	10.9
2014-04-01	11.2
2014-07-01	10.0
2014-10-01	10.0
2015-01-01	10.2
2015-04-01	8.5
2015-07-01	7.8
2015-10-01	8.5
2016-01-01	7.9
2016-04-01	7.7
2016-07-01	6.4
2016-10-01	6.5
2017-01-01	6.6
2017-04-01	5.5
2017-07-01	5.5
2017-10-01	5.7
2018-01-01	5.7
2018-04-01	5.0