Quarter	Percent
1999-01-01	11.6
2000-01-01	16.3
2000-04-01	16.3
2000-07-01	15.5
2000-10-01	15.9
2001-01-01	17.1
2001-04-01	17.7
2001-07-01	17.1
2001-10-01	17.3
2002-01-01	18.4
2002-04-01	18.4
2002-07-01	18.5
2002-10-01	18.2
2003-01-01	18.7
2003-04-01	17.5
2003-07-01	18
2003-10-01	18
2004-01-01	18.7
2004-04-01	17.6
2004-07-01	17
2004-10-01	17.4
2005-01-01	17.7
2005-04-01	17.3
2005-07-01	17.8
2005-10-01	16.9
2006-01-01	15.1
2006-04-01	13.5
2006-07-01	12.9
2006-10-01	12.1
2007-01-01	10.7
2007-04-01	8.9
2007-07-01	8.4
2007-10-01	8.3
2008-01-01	7.5
2008-04-01	6.7
2008-07-01	6.7
2008-10-01	6.5
2009-01-01	7.9
2009-04-01	7.4
2009-07-01	7.3
2009-10-01	7.7
2010-01-01	9.4
2010-04-01	8.5
2010-07-01	8.3
2010-10-01	8.6
2011-01-01	8.9
2011-04-01	9.0
2011-07-01	9.1
2011-10-01	9.4
2012-01-01	9.7
2012-04-01	9.6
2012-07-01	9.7
2012-10-01	9.7
2013-01-01	10.7
2013-04-01	10.3
2013-07-01	9.7
2013-10-01	9.4
2014-01-01	10
2014-04-01	8.9
2014-07-01	8.0
2014-10-01	7.9
2015-01-01	8.1
2015-04-01	7.1
2015-07-01	6.8
2015-10-01	6.5
2016-01-01	6.4
2016-04-01	5.7
2016-07-01	5.6
2016-10-01	5.1
2017-01-01	4.8
2017-04-01	4.3
2017-07-01	4.4
2017-10-01	4.0
2018-01-01	3.9
2018-04-01	3.3