Quarter	Percent
1998-01-01	11.1
1998-04-01	10.8
1998-07-01	14.5
1998-10-01	15.6
1999-01-01	17.4
1999-04-01	16.6
1999-07-01	19.1
1999-10-01	19
2000-01-01	18.5
2000-04-01	17
2000-07-01	18.4
2000-10-01	18.5
2001-01-01	17.8
2001-04-01	16.3
2001-07-01	18.5
2001-10-01	17.6
2002-01-01	17.4
2002-04-01	15.4
2002-07-01	17.8
2002-10-01	16.9
2003-01-01	18
2003-04-01	16.8
2003-07-01	19.4
2003-10-01	20
2004-01-01	20.8
2004-04-01	19.9
2004-07-01	21.6
2004-10-01	21.8
2005-01-01	20.9
2005-04-01	17.9
2005-07-01	18.9
2005-10-01	19.1
2006-01-01	19.5
2006-04-01	17
2006-07-01	18.1
2006-10-01	15.4
2007-01-01	12.1
2007-04-01	10.3
2007-07-01	10.7
2007-10-01	9.8
2008-01-01	10.1
2008-04-01	8.6
2008-07-01	10.3
2008-10-01	10.4
2009-01-01	13
2009-04-01	14.8
2009-07-01	18.3
2009-10-01	20.2
2010-01-01	19.7
2010-04-01	17.9
2010-07-01	18.4
2010-10-01	17.4
2011-01-01	17.3
2011-04-01	18
2011-07-01	18.5
2011-10-01	18.5
2012-01-01	19.4
2012-04-01	19.2
2012-07-01	19.5
2012-10-01	20
2013-01-01	19.2
2013-04-01	17.6
2013-07-01	19.6
2013-10-01	19.5
2014-01-01	16.5
2014-04-01	15.5
2014-07-01	16.3
2014-10-01	15
2015-01-01	13.9
2015-04-01	12.0
2015-07-01	12.9
2015-10-01	11.4
2016-01-01	9.7
2016-04-01	10.0
2016-07-01	11.4
2016-10-01	10.8
2017-01-01	8.5
2017-04-01	8.3
2017-07-01	8.7
2017-10-01	6.3
2018-01-01	6.4
2018-04-01	7.0