Quarter	Percent
1999-04-01	38.3
1999-07-01	37.6
1999-10-01	37.8
2000-01-01	38.1
2000-04-01	38.1
2000-07-01	37.5
2000-10-01	37.9
2001-01-01	38.2
2001-04-01	38.5
2001-07-01	37.8
2001-10-01	37.9
2002-01-01	38.4
2002-04-01	38.2
2002-07-01	37.7
2002-10-01	37.8
2003-01-01	38.2
2003-04-01	38.1
2003-07-01	37.6
2003-10-01	37.8
2004-01-01	38
2004-04-01	38.1
2004-07-01	37.8
2004-10-01	37.8
2005-01-01	37.8
2005-04-01	38.1
2005-07-01	37.5
2005-10-01	37.6
2006-01-01	37.6
2006-04-01	37.5
2006-07-01	36.9
2006-10-01	37.3
2007-01-01	37.7
2007-04-01	37.7
2007-07-01	37.2
2007-10-01	37.3
2008-01-01	37.4
2008-04-01	37.4
2008-07-01	37
2008-10-01	37.1
2009-01-01	37.3
2009-04-01	37.6
2009-07-01	37.2
2009-10-01	37.6
2010-01-01	38
2010-04-01	37.9
2010-07-01	37.2
2010-10-01	37.6
2011-01-01	37.8
2011-04-01	37.8
2011-07-01	37.5
2011-10-01	37.6
2012-01-01	37.9
2012-04-01	37.8
2012-07-01	37.2
2012-10-01	37.2
2013-01-01	37.6
2013-04-01	37.6
2013-07-01	37
2013-10-01	37.3
2014-01-01	37.4
2014-04-01	37.5
2014-07-01	37.0
2014-10-01	37.4
2015-01-01	37.3
2015-04-01	37.6
2015-07-01	37.0
2015-10-01	37.1
2016-01-01	37.3
2016-04-01	37.2
2016-07-01	36.8
2016-10-01	37.1
2017-01-01	37.2
2017-04-01	37.2
2017-07-01	37.0
2017-10-01	37.0
2018-01-01	37.0
2018-04-01	37.2