Quarter	Percent
2000-04-01	32.4
2001-04-01	32.4
2002-04-01	31.8
2003-04-01	31.1
2004-04-01	30.8
2005-01-01	30.4
2005-04-01	30.1
2005-07-01	30.0
2005-10-01	29.9
2006-01-01	29.9
2006-04-01	29.7
2006-07-01	29.4
2006-10-01	29.4
2007-01-01	29.6
2007-04-01	29.3
2007-07-01	28.9
2007-10-01	29
2008-01-01	29.1
2008-04-01	28.8
2008-07-01	28.6
2008-10-01	28.6
2009-01-01	28.8
2009-04-01	28.6
2009-07-01	28.7
2009-10-01	28.6
2010-01-01	28.8
2010-04-01	28.6
2010-07-01	28.7
2010-10-01	28.6
2011-01-01	28.8
2011-04-01	28.6
2011-07-01	28.5
2011-10-01	28.3
2012-01-01	28.4
2012-04-01	28
2012-07-01	27.9
2012-10-01	27.8
2013-01-01	28
2013-04-01	27.8
2013-07-01	27.8
2013-10-01	27.7
2014-01-01	27.9
2014-04-01	27.8
2014-07-01	27.6
2014-10-01	27.4
2015-01-01	27.7
2015-04-01	27.6
2015-07-01	27.5
2015-10-01	27.3
2016-01-01	27.5
2016-04-01	27.2
2016-07-01	27.0
2016-10-01	27.0
2017-01-01	27.3
2017-04-01	27.0
2017-07-01	26.7
2017-10-01	26.7
2018-01-01	26.9
2018-04-01	26.6