Quarter	Percent
2000-04-01	22.8
2001-04-01	23.0
2002-04-01	22.7
2003-04-01	22.4
2004-04-01	22.4
2005-01-01	22.3
2005-04-01	22.0
2005-07-01	21.7
2005-10-01	21.9
2006-01-01	22.0
2006-04-01	21.8
2006-07-01	21.5
2006-10-01	21.7
2007-01-01	21.9
2007-04-01	21.6
2007-07-01	21.1
2007-10-01	21.6
2008-01-01	21.7
2008-04-01	21.4
2008-07-01	21.1
2008-10-01	21.5
2009-01-01	21.8
2009-04-01	21.6
2009-07-01	21.7
2009-10-01	21.8
2010-01-01	22.0
2010-04-01	21.8
2010-07-01	21.9
2010-10-01	22.0
2011-01-01	22.3
2011-04-01	22.1
2011-07-01	22.0
2011-10-01	21.9
2012-01-01	22.2
2012-04-01	21.8
2012-07-01	21.6
2012-10-01	21.7
2013-01-01	22.1
2013-04-01	21.8
2013-07-01	21.8
2013-10-01	21.9
2014-01-01	22.2
2014-04-01	22.1
2014-07-01	21.8
2014-10-01	21.8
2015-01-01	22.1
2015-04-01	22.0
2015-07-01	21.7
2015-10-01	21.7
2016-01-01	22.1
2016-04-01	21.7
2016-07-01	21.5
2016-10-01	21.6
2017-01-01	22.0
2017-04-01	21.6
2017-07-01	21.2
2017-10-01	21.3
2018-01-01	21.6
2018-04-01	21.3