Quarter	Percent
1998-01-01	6.0
1998-04-01	4.7
1998-07-01	4.8
1998-10-01	4.9
1999-01-01	4.9
1999-04-01	4.6
1999-07-01	4.4
1999-10-01	4.4
2000-01-01	4.5
2000-04-01	3.9
2000-07-01	4.1
2000-10-01	3.8
2001-01-01	4.2
2001-04-01	3.9
2001-07-01	4.0
2001-10-01	4.2
2002-01-01	4.4
2002-04-01	4.6
2002-07-01	5.1
2002-10-01	6.2
2003-01-01	6.4
2003-04-01	6.2
2003-07-01	6.2
2003-10-01	6.6
2004-01-01	6.4
2004-04-01	6.4
2004-07-01	6.9
2004-10-01	7.1
2005-01-01	7.6
2005-04-01	7.3
2005-07-01	7.8
2005-10-01	8.1
2006-01-01	7.8
2006-04-01	7.4
2006-07-01	7.6
2006-10-01	8.3
2007-01-01	8.5
2007-04-01	8.0
2007-07-01	8.0
2007-10-01	7.9
2008-01-01	7.7
2008-04-01	7.4
2008-07-01	7.8
2008-10-01	7.9
2009-01-01	9.0
2009-04-01	9.2
2009-07-01	10
2009-10-01	10.2
2010-01-01	10.7
2010-04-01	10.8
2010-07-01	11.1
2010-10-01	11.3
2011-01-01	12.6
2011-04-01	12.3
2011-07-01	12.6
2011-10-01	14.1
2012-01-01	15
2012-04-01	15.1
2012-07-01	15.9
2012-10-01	17.1
2013-01-01	17.8
2013-04-01	16.7
2013-07-01	15.8
2013-10-01	15.5
2014-01-01	15.3
2014-04-01	14.1
2014-07-01	13.3
2014-10-01	13.6
2015-01-01	13.9
2015-04-01	12.1
2015-07-01	12.1
2015-10-01	12.4
2016-01-01	12.6
2016-04-01	11.0
2016-07-01	10.7
2016-10-01	10.6
2017-01-01	10.2
2017-04-01	9.0
2017-07-01	8.6
2017-10-01	8.2
2018-01-01	8.0
2018-04-01	6.8