Quarter	Percent
1998-01-01	8.1
1998-04-01	7.1
1998-07-01	6.9
1998-10-01	7.5
1999-01-01	8.3
1999-04-01	7.7
1999-07-01	7.7
1999-10-01	8.6
2000-01-01	8.2
2000-04-01	7.4
2000-07-01	7.1
2000-10-01	7.2
2001-01-01	7.5
2001-04-01	6.9
2001-07-01	6.9
2001-10-01	7.7
2002-01-01	7.7
2002-04-01	6.4
2002-07-01	6.3
2002-10-01	6.7
2003-01-01	6.9
2003-04-01	6.0
2003-07-01	5.8
2003-10-01	6.2
2004-01-01	7.5
2004-04-01	6.4
2004-07-01	6.2
2004-10-01	6.5
2005-01-01	6.6
2005-04-01	5.9
2005-07-01	6.1
2005-10-01	6.2
2006-01-01	6.4
2006-04-01	5.6
2006-07-01	5.2
2006-10-01	5.6
2007-01-01	5.8
2007-04-01	5.0
2007-07-01	4.9
2007-10-01	5.3
2008-01-01	5.6
2008-04-01	4.7
2008-07-01	4.8
2008-10-01	5.4
2009-01-01	6.9
2009-04-01	6.5
2009-07-01	6.7
2009-10-01	7.8
2010-01-01	9.2
2010-04-01	9.5
2010-07-01	9.9
2010-10-01	11.7
2011-01-01	13.5
2011-04-01	13.9
2011-07-01	15.2
2011-10-01	18.1
2012-01-01	19.9
2012-04-01	21
2012-07-01	21.9
2012-10-01	23.5
2013-01-01	24.9
2013-04-01	24.4
2013-07-01	24.1
2013-10-01	24.7
2014-01-01	25
2014-04-01	23.6
2014-07-01	22.7
2014-10-01	23.3
2015-01-01	23.5
2015-04-01	21.6
2015-07-01	20.7
2015-10-01	21.2
2016-01-01	21.2
2016-04-01	19.5
2016-07-01	18.9
2016-10-01	19.9
2017-01-01	19.8
2017-04-01	17.7
2017-07-01	16.5
2017-10-01	17.4
2018-01-01	17.3
2018-04-01	15.3