Quarter	Percent
1999-04-01	12.4
2000-01-01	16.1
2000-04-01	14.6
2000-07-01	15.5
2000-10-01	14.4
2001-01-01	14.2
2001-04-01	13.1
2001-07-01	13
2001-10-01	13.1
2002-01-01	13.9
2002-04-01	10.3
2002-07-01	10
2002-10-01	14.7
2003-01-01	12.8
2003-04-01	10.9
2003-07-01	8.9
2003-10-01	7.8
2004-01-01	10
2004-04-01	10.2
2004-07-01	9.2
2004-10-01	9.5
2005-01-01	11.3
2005-04-01	9.7
2005-07-01	6.0
2005-10-01	7.6
2006-01-01	8.1
2006-04-01	5.3
2006-07-01	4.5
2006-10-01	5.0
2007-01-01	4.9
2007-04-01	4.6
2007-07-01	3.4
2007-10-01	3.8
2008-01-01	2.8
2008-04-01	3.8
2008-07-01	6.2
2008-10-01	6.8
2009-01-01	12.7
2009-04-01	15.7
2009-07-01	15.5
2009-10-01	19.2
2010-01-01	23.1
2010-04-01	19.9
2010-07-01	14.1
2010-10-01	12.6
2011-01-01	13.6
2011-04-01	12.1
2011-07-01	9.6
2011-10-01	10.4
2012-01-01	10.7
2012-04-01	9.4
2012-07-01	9.1
2012-10-01	9.9
2013-01-01	9.6
2013-04-01	7.4
2013-07-01	8.1
2013-10-01	8.2
2014-01-01	8.4
2014-04-01	6.0
2014-07-01	8.2
2014-10-01	5.9
2015-01-01	6.9
2015-04-01	5.8
2015-07-01	3.4
2015-10-01	5.3
2016-01-01	6.0
2016-04-01	6.4
2016-07-01	6.4
2016-10-01	5.9
2017-01-01	4.5
2017-04-01	7.0
2017-07-01	4.3
2017-10-01	4.9
2018-01-01	6.7
2018-04-01	3.4