Quarter	Percent
1998-04-01	13.4
1998-10-01	12.5
1999-04-01	13.1
1999-10-01	15.2
2000-04-01	15.0
2000-10-01	15.5
2001-04-01	13.7
2001-10-01	13.9
2002-01-01	13.7
2002-04-01	13.9
2002-07-01	10.5
2002-10-01	12.8
2003-01-01	11.1
2003-04-01	11.9
2003-07-01	11.5
2003-10-01	9.6
2004-01-01	11.6
2004-04-01	11.0
2004-07-01	11.1
2004-10-01	11.0
2005-01-01	10.4
2005-04-01	9.4
2005-07-01	10.1
2005-10-01	8.5
2006-01-01	7.4
2006-04-01	6.3
2006-07-01	6.0
2006-10-01	6.2
2007-01-01	8.1
2007-04-01	6.1
2007-07-01	4.9
2007-10-01	5.3
2008-01-01	7.1
2008-04-01	5.8
2008-07-01	7.6
2008-10-01	10.6
2009-01-01	15.9
2009-04-01	20.0
2009-07-01	19.3
2009-10-01	21.3
2010-01-01	24.8
2010-04-01	21.8
2010-07-01	19.2
2010-10-01	19.1
2011-01-01	19.3
2011-04-01	18.8
2011-07-01	15.2
2011-10-01	16.1
2012-01-01	17.0
2012-04-01	15.4
2012-07-01	11.8
2012-10-01	15.2
2013-01-01	14.1
2013-04-01	11.3
2013-07-01	11.0
2013-10-01	10.9
2014-01-01	13.0
2014-04-01	11.8
2014-07-01	10.2
2014-10-01	9.7
2015-01-01	11.3
2015-04-01	10.8
2015-07-01	10.2
2015-10-01	9.4
2016-01-01	10.6
2016-04-01	8.8
2016-07-01	9.7
2016-10-01	10.2
2017-01-01	9.7
2017-04-01	9.8
2017-07-01	8.5
2017-10-01	8.0
2018-01-01	8.4
2018-04-01	9.0