Quarter	Percent
1999-01-01	18.6
1999-04-01	17.2
1999-07-01	16.3
1999-10-01	16.6
2000-01-01	16
2000-04-01	14.8
2000-07-01	13.8
2000-10-01	13.9
2001-01-01	16.5
2001-04-01	15
2001-07-01	12.9
2001-10-01	18.5
2002-01-01	16.9
2002-04-01	13.5
2002-07-01	14.3
2002-10-01	15.5
2003-01-01	17.6
2003-04-01	13.1
2003-07-01	16.6
2003-10-01	15
2004-01-01	15.2
2004-04-01	11.2
2004-07-01	12.5
2004-10-01	16.5
2005-01-01	14.6
2005-04-01	11
2005-07-01	15.3
2005-10-01	17
2006-01-01	13.1
2006-04-01	13.6
2006-07-01	8.5
2006-10-01	11.9
2007-01-01	10.1
2007-04-01	7.3
2007-07-01	8.2
2007-10-01	12
2008-01-01	12.2
2008-04-01	7.9
2008-07-01	9.0
2008-10-01	10.5
2009-01-01	14.8
2009-04-01	10.7
2009-07-01	13.1
2009-10-01	16.5
2010-01-01	16.7
2010-04-01	16.5
2010-07-01	13
2010-10-01	14.8
2011-01-01	17.6
2011-04-01	12.5
2011-07-01	13.5
2011-10-01	16.6
2012-01-01	16.9
2012-04-01	17.3
2012-07-01	21.5
2012-10-01	24.9
2013-01-01	21.7
2013-04-01	20.8
2013-07-01	18.7
2013-10-01	19.3
2014-01-01	24.3
2014-04-01	17.6
2014-07-01	17
2014-10-01	19.0
2015-01-01	17.9
2015-04-01	18.7
2015-07-01	13.2
2015-10-01	21.1
2016-01-01	20.0
2016-04-01	13.9
2016-07-01	13.5
2016-10-01	15.3
2017-01-01	12.3
2017-04-01	9.5
2017-07-01	6.7
2017-10-01	12.0
2018-01-01	9.0
2018-04-01	7.1