Quarter	Percent
1998-04-01	15.6
1998-10-01	13.6
1999-04-01	14.3
1999-10-01	15.6
2000-04-01	15.3
2000-10-01	15.7
2001-04-01	15.4
2001-10-01	14.7
2002-01-01	13.8
2002-04-01	15.2
2002-07-01	11.2
2002-10-01	13.3
2003-01-01	11.7
2003-04-01	12.4
2003-07-01	12.6
2003-10-01	10.4
2004-01-01	12.5
2004-04-01	11.3
2004-07-01	11.5
2004-10-01	11.5
2005-01-01	11.1
2005-04-01	10.9
2005-07-01	9.7
2005-10-01	9.1
2006-01-01	8.6
2006-04-01	8.1
2006-07-01	6.7
2006-10-01	6.5
2007-01-01	8.3
2007-04-01	6.9
2007-07-01	5.9
2007-10-01	5.7
2008-01-01	7.7
2008-04-01	6.9
2008-07-01	8.1
2008-10-01	12.2
2009-01-01	17.9
2009-04-01	21.4
2009-07-01	22.2
2009-10-01	24.0
2010-01-01	27.2
2010-04-01	24.2
2010-07-01	21.2
2010-10-01	19.7
2011-01-01	20.5
2011-04-01	20.5
2011-07-01	17.4
2011-10-01	17.4
2012-01-01	18.0
2012-04-01	17.6
2012-07-01	14.4
2012-10-01	15.9
2013-01-01	14.9
2013-04-01	12.2
2013-07-01	12.1
2013-10-01	12.0
2014-01-01	14.0
2014-04-01	12.4
2014-07-01	11.3
2014-10-01	10.6
2015-01-01	11.2
2015-04-01	11.7
2015-07-01	11.4
2015-10-01	11.2
2016-01-01	11.3
2016-04-01	10.9
2016-07-01	11.4
2016-10-01	11.0
2017-01-01	10.8
2017-04-01	10.5
2017-07-01	9.1
2017-10-01	9.1
2018-01-01	9.1
2018-04-01	9.4