Quarter	Percent
1999-04-01	14.2
1999-07-01	15.8
1999-10-01	13.6
2000-01-01	13.3
2000-04-01	13.5
2000-07-01	14.5
2000-10-01	13.5
2001-01-01	13.4
2001-04-01	11.8
2001-07-01	14.3
2001-10-01	13.3
2002-01-01	13.3
2002-04-01	12.8
2002-07-01	14.7
2002-10-01	13.7
2003-01-01	14
2003-04-01	13.1
2003-07-01	14.9
2003-10-01	13.3
2004-01-01	12.8
2004-04-01	11.6
2004-07-01	14.6
2004-10-01	13.7
2005-01-01	13.5
2005-04-01	13.1
2005-07-01	15.2
2005-10-01	15.4
2006-01-01	15.2
2006-04-01	15.4
2006-07-01	16.9
2006-10-01	15.1
2007-01-01	15.7
2007-04-01	15.7
2007-07-01	17.1
2007-10-01	14.9
2008-01-01	15.5
2008-04-01	15.8
2008-07-01	18.6
2008-10-01	18.1
2009-01-01	20.3
2009-04-01	21.6
2009-07-01	23.8
2009-10-01	21.8
2010-01-01	23.2
2010-04-01	21.4
2010-07-01	21.5
2010-10-01	21.8
2011-01-01	22
2011-04-01	22.2
2011-07-01	25.8
2011-10-01	25
2012-01-01	25.1
2012-04-01	23.8
2012-07-01	23.8
2012-10-01	23
2013-01-01	22.5
2013-04-01	23.4
2013-07-01	24.1
2013-10-01	21.9
2014-01-01	20.8
2014-04-01	18.3
2014-07-01	19.1
2014-10-01	17.6
2015-01-01	17.2
2015-04-01	16.9
2015-07-01	16.5
2015-10-01	14.2
2016-01-01	14.1
2016-04-01	14.6
2016-07-01	16.0
2016-10-01	14.3
2017-01-01	13.6
2017-04-01	13.0
2017-07-01	14.4
2017-10-01	12.9
2018-01-01	12.4
2018-04-01	11.5