Quarter	Percent
1999-01-01	12.3
1999-04-01	10.8
1999-07-01	10.5
1999-10-01	10.6
2000-01-01	10.5
2000-04-01	9.5
2000-07-01	9.3
2000-10-01	9.4
2001-01-01	8.0
2001-04-01	7.4
2001-07-01	7.3
2001-10-01	7.7
2002-01-01	8.4
2002-04-01	7.9
2002-07-01	8.4
2002-10-01	8.7
2003-01-01	8.8
2003-04-01	8.3
2003-07-01	8.4
2003-10-01	8.6
2004-01-01	8.7
2004-04-01	8.4
2004-07-01	8.2
2004-10-01	7.9
2005-01-01	7.9
2005-04-01	7.5
2005-07-01	6.6
2005-10-01	6.8
2006-01-01	6.9
2006-04-01	6.4
2006-07-01	6.1
2006-10-01	6.2
2007-01-01	6.4
2007-04-01	6.2
2007-07-01	6.3
2007-10-01	6.9
2008-01-01	8.0
2008-04-01	9.1
2008-07-01	10.4
2008-10-01	13
2009-01-01	17
2009-04-01	17.7
2009-07-01	17.7
2009-10-01	18.7
2010-01-01	19.9
2010-04-01	19.7
2010-07-01	19.2
2010-10-01	19.9
2011-01-01	20.7
2011-04-01	20.5
2011-07-01	21
2011-10-01	22.4
2012-01-01	24.1
2012-04-01	24.6
2012-07-01	24.7
2012-10-01	25.6
2013-01-01	26.8
2013-04-01	25.6
2013-07-01	25.3
2013-10-01	25.2
2014-01-01	25.5
2014-04-01	23.8
2014-07-01	22.7
2014-10-01	22.9
2015-01-01	22.9
2015-04-01	21.1
2015-07-01	20.0
2015-10-01	19.6
2016-01-01	19.6
2016-04-01	18.5
2016-07-01	17.5
2016-10-01	17.3
2017-01-01	17.3
2017-04-01	15.8
2017-07-01	14.9
2017-10-01	15.1
2018-01-01	15.3
2018-04-01	13.8
2018-07-01	13.2