Quarter	Percent
1997-01-01	10.7
1997-04-01	10
1997-07-01	9.0
1997-10-01	8.8
1998-01-01	9.6
1998-04-01	9.5
1998-07-01	8.6
1998-10-01	9.0
1999-01-01	10.6
1999-04-01	11.6
1999-07-01	11.2
1999-10-01	12.1
2000-01-01	16.1
2000-04-01	13.4
2000-07-01	14.2
2000-10-01	14.9
2001-01-01	14.1
2001-04-01	13.1
2001-07-01	12.5
2001-10-01	12.3
2002-01-01	11.9
2002-04-01	10
2002-07-01	10.6
2002-10-01	12.4
2003-01-01	11.2
2003-04-01	11.3
2003-07-01	9.7
2003-10-01	9.1
2004-01-01	10.3
2004-04-01	10.2
2004-07-01	10.5
2004-10-01	9.5
2005-01-01	9.6
2005-04-01	8.4
2005-07-01	7.0
2005-10-01	7.1
2006-01-01	6.6
2006-04-01	6.2
2006-07-01	5.4
2006-10-01	5.5
2007-01-01	5.3
2007-04-01	4.9
2007-07-01	4.1
2007-10-01	4.1
2008-01-01	4.1
2008-04-01	4.0
2008-07-01	6.2
2008-10-01	7.4
2009-01-01	11.2
2009-04-01	13.2
2009-07-01	14.4
2009-10-01	15.5
2010-01-01	19.5
2010-04-01	18.3
2010-07-01	15.4
2010-10-01	13.6
2011-01-01	14.3
2011-04-01	13
2011-07-01	10.7
2011-10-01	11.3
2012-01-01	11.3
2012-04-01	10.1
2012-07-01	9.5
2012-10-01	9.1
2013-01-01	10
2013-04-01	8.0
2013-07-01	7.8
2013-10-01	8.7
2014-01-01	8.5
2014-04-01	7.0
2014-07-01	7.5
2014-10-01	6.3
2015-01-01	6.6
2015-04-01	6.5
2015-07-01	5.2
2015-10-01	6.4
2016-01-01	6.5
2016-04-01	6.5
2016-07-01	7.5
2016-10-01	6.6
2017-01-01	5.6
2017-04-01	7.0
2017-07-01	5.2
2017-10-01	5.3
2018-01-01	6.8
2018-04-01	5.1