Quarter	Percent
1998-04-01	18.1
1999-04-01	17.1
2000-04-01	10.8
2001-01-01	13
2001-04-01	12.7
2001-07-01	11.8
2001-10-01	12.9
2002-01-01	16.1
2002-04-01	13.4
2002-07-01	12.1
2002-10-01	14
2003-01-01	15.4
2003-04-01	15.5
2003-07-01	12.2
2003-10-01	15.3
2004-01-01	20.2
2004-04-01	19.8
2004-07-01	15.1
2004-10-01	17.1
2005-01-01	18.8
2005-04-01	28.1
2005-07-01	20.2
2005-10-01	19.8
2006-01-01	22.9
2006-04-01	26.2
2006-07-01	17.2
2006-10-01	17.4
2007-01-01	21.4
2007-04-01	22.3
2007-07-01	15.2
2007-10-01	16.4
2008-01-01	19.4
2008-04-01	24.6
2008-07-01	16
2008-10-01	18.6
2009-01-01	24.9
2009-04-01	30
2009-07-01	23.8
2009-10-01	26
2010-01-01	29.3
2010-04-01	30.7
2010-07-01	21.3
2010-10-01	22.3
2011-01-01	24.6
2011-04-01	26.9
2011-07-01	19.5
2011-10-01	22.1
2012-01-01	25.8
2012-04-01	28.7
2012-07-01	21.8
2012-10-01	23.6
2013-01-01	27.7
2013-04-01	29.5
2013-07-01	19.7
2013-10-01	22.1
2014-01-01	26.2
2014-04-01	29.5
2014-07-01	19.3
2014-10-01	21.7
2015-01-01	23.8
2015-04-01	26.0
2015-07-01	17.7
2015-10-01	17.1
2016-01-01	24.2
2016-04-01	24.7
2016-07-01	16.3
2016-10-01	16.4
2017-01-01	21.7
2017-04-01	22.9
2017-07-01	15.5
2017-10-01	14.9
2018-01-01	19.0
2018-04-01	22.8