Quarter	Percent
1998-04-01	20.4
1999-01-01	21.8
1999-04-01	22.6
1999-07-01	22.2
1999-10-01	17.5
2000-01-01	16.3
2000-04-01	15.2
2000-07-01	21.3
2000-10-01	16.9
2001-01-01	14.8
2001-04-01	15.3
2001-07-01	17.8
2001-10-01	19.6
2002-01-01	17.8
2002-04-01	15.7
2002-07-01	18.9
2002-10-01	18.4
2003-01-01	20.8
2003-04-01	19
2003-07-01	24.5
2003-10-01	22.6
2004-01-01	19.6
2004-04-01	17.5
2004-07-01	25
2004-10-01	22.3
2005-01-01	20.5
2005-04-01	19.9
2005-07-01	23.4
2005-10-01	22.1
2006-01-01	20
2006-04-01	18.9
2006-07-01	23
2006-10-01	20
2007-01-01	18.6
2007-04-01	19.2
2007-07-01	20.3
2007-10-01	17.4
2008-01-01	16.5
2008-04-01	14.3
2008-07-01	22.7
2008-10-01	17.8
2009-01-01	20.8
2009-04-01	19.8
2009-07-01	24
2009-10-01	23
2010-01-01	24.8
2010-04-01	21.1
2010-07-01	22.5
2010-10-01	21.2
2011-01-01	18.7
2011-04-01	16.4
2011-07-01	23
2011-10-01	16.6
2012-01-01	18.8
2012-04-01	16.2
2012-07-01	21.7
2012-10-01	22
2013-01-01	23.3
2013-04-01	22.5
2013-07-01	24.5
2013-10-01	24.4
2014-01-01	26.3
2014-04-01	23.4
2014-07-01	21.3
2014-10-01	22.2
2015-01-01	20.4
2015-04-01	20.4
2015-07-01	22.2
2015-10-01	25.4
2016-01-01	19.8
2016-04-01	19.2
2016-07-01	21.8
2016-10-01	19.7
2017-01-01	21.4
2017-04-01	19.9
2017-07-01	19.1
2017-10-01	16.8
2018-01-01	16.9
2018-04-01	18.0
