Quarter	Percent
1999-01-01	17.5
1999-04-01	19.8
1999-07-01	16.6
1999-10-01	18.5
2000-01-01	21.4
2000-04-01	18.5
2000-07-01	16.3
2000-10-01	18.4
2001-01-01	19.1
2001-04-01	16.6
2001-07-01	20.5
2001-10-01	25.4
2002-01-01	19.3
2002-04-01	16.7
2002-07-01	19
2002-10-01	19.2
2003-01-01	21.4
2003-04-01	18.4
2003-07-01	19
2003-10-01	20.3
2004-01-01	22
2004-04-01	17.7
2004-07-01	16.3
2004-10-01	21.1
2005-01-01	21.3
2005-04-01	15.5
2005-07-01	16
2005-10-01	18.1
2006-01-01	24
2006-04-01	15.7
2006-07-01	14.8
2006-10-01	12.8
2007-01-01	13.4
2007-04-01	8.8
2007-07-01	9.5
2007-10-01	13.4
2008-01-01	13.5
2008-04-01	11.3
2008-07-01	9.3
2008-10-01	11.6
2009-01-01	13.7
2009-04-01	14.4
2009-07-01	12.4
2009-10-01	13.2
2010-01-01	11.7
2010-04-01	14.6
2010-07-01	12.9
2010-10-01	16.2
2011-01-01	20.2
2011-04-01	14.3
2011-07-01	14.2
2011-10-01	18.4
2012-01-01	21.3
2012-04-01	17.8
2012-07-01	20.9
2012-10-01	23.6
2013-01-01	25.5
2013-04-01	28.8
2013-07-01	18.8
2013-10-01	22.1
2014-01-01	23.4
2014-04-01	20.8
2014-07-01	20.1
2014-10-01	21.1
2015-01-01	20.9
2015-04-01	11.8
2015-07-01	12.6
2015-10-01	14.0
2016-01-01	14.9
2016-04-01	13.5
2016-07-01	13.9
2016-10-01	16.7
2017-01-01	10.5
2017-04-01	10.8
2017-07-01	16.5
2017-10-01	13.5
2018-01-01	12.9
2018-04-01	9.4