Quarter	Percent
1999-04-01	6.1
1999-07-01	5.8
1999-10-01	5.3
2000-01-01	4.9
2000-04-01	4.5
2000-07-01	4.5
2000-10-01	4.1
2001-01-01	3.8
2001-04-01	3.9
2001-07-01	4.4
2001-10-01	4.3
2002-01-01	4.8
2002-04-01	4.7
2002-07-01	4.9
2002-10-01	4.9
2003-01-01	5.1
2003-04-01	4.9
2003-07-01	5.5
2003-10-01	5.0
2004-01-01	4.8
2004-04-01	5.1
2004-07-01	5.2
2004-10-01	4.8
2005-01-01	4.5
2005-04-01	4.7
2005-07-01	4.9
2005-10-01	4.6
2006-01-01	4.4
2006-04-01	4.6
2006-07-01	5.1
2006-10-01	4.5
2007-01-01	5.0
2007-04-01	5.1
2007-07-01	5.1
2007-10-01	5.3
2008-01-01	6.1
2008-04-01	7.0
2008-07-01	8.4
2008-10-01	9.7
2009-01-01	13.3
2009-04-01	15.9
2009-07-01	16.3
2009-10-01	16.4
2010-01-01	17
2010-04-01	17.5
2010-07-01	17.5
2010-10-01	18
2011-01-01	18.0
2011-04-01	18.2
2011-07-01	18.4
2011-10-01	18.1
2012-01-01	18.5
2012-04-01	18.8
2012-07-01	18.4
2012-10-01	17.0
2013-01-01	16.2
2013-04-01	16.2
2013-07-01	15.2
2013-10-01	13.5
2014-01-01	14.0
2014-04-01	13.8
2014-07-01	12.8
2014-10-01	11.6
2015-01-01	11.7
2015-04-01	11.3
2015-07-01	10.9
2015-10-01	10.5
2016-01-01	10.1
2016-04-01	10.0
2016-07-01	9.3
2016-10-01	7.8
2017-01-01	7.5
2017-04-01	7.7
2017-07-01	7.3
2017-10-01	6.7
2018-01-01	6.0
2018-04-01	6.4