Quarter	Percent
1998-01-01	34.6
1998-04-01	34.6
1998-07-01	34.4
1998-10-01	34.7
1999-01-01	34.6
1999-04-01	35
1999-07-01	35.1
1999-10-01	35.2
2000-01-01	35.3
2000-04-01	35.1
2000-07-01	35.2
2000-10-01	35.5
2001-01-01	35.9
2001-04-01	35.9
2001-07-01	35.9
2001-10-01	36
2002-01-01	36.2
2002-04-01	35.9
2002-07-01	35.8
2002-10-01	35.8
2003-01-01	35.5
2003-04-01	35.6
2003-07-01	35.7
2003-10-01	35.8
2004-01-01	35.6
2004-04-01	35.5
2004-07-01	35.7
2004-10-01	35.8
2005-01-01	35.7
2005-04-01	35.7
2005-07-01	35.7
2005-10-01	35.7
2006-01-01	35.5
2006-04-01	35.6
2006-07-01	35.7
2006-10-01	35.8
2007-01-01	35.9
2007-04-01	36
2007-07-01	35.7
2007-10-01	35.8
2008-01-01	35.8
2008-04-01	35.7
2008-07-01	35.8
2008-10-01	36
2009-01-01	36
2009-04-01	36
2009-07-01	35.8
2009-10-01	36.1
2010-01-01	36.1
2010-04-01	36.3
2010-07-01	36.5
2010-10-01	36.8
2011-01-01	37.3
2011-04-01	37.6
2011-07-01	37.9
2011-10-01	38.5
2012-01-01	38.6
2012-04-01	38.7
2012-07-01	38.8
2012-10-01	38.8
2013-01-01	39.1
2013-04-01	38.9
2013-07-01	39
2013-10-01	39.4
2014-01-01	39.5
2014-04-01	39.8
2014-07-01	39.8
2014-10-01	40.4
2015-01-01	40.5
2015-04-01	40.3
2015-07-01	39.9
2015-10-01	40.1
2016-01-01	40.3
2016-04-01	40.1
2016-07-01	39.9
2016-10-01	40.4
2017-01-01	40.2
2017-04-01	40.0
2017-07-01	39.7
2017-10-01	40.2
2018-01-01	40.2
2018-04-01	39.9