Quarter	Percent
1999-04-01	45.7
1999-07-01	42.8
1999-10-01	44.6
2000-01-01	44.8
2000-04-01	44.4
2000-07-01	41.9
2000-10-01	43.6
2001-01-01	43.9
2001-04-01	44
2001-07-01	41
2001-10-01	42.8
2002-01-01	42.6
2002-04-01	42.7
2002-07-01	41
2002-10-01	42.6
2003-01-01	42.6
2003-04-01	42.4
2003-07-01	40.3
2003-10-01	41.6
2004-01-01	41.9
2004-04-01	42
2004-07-01	40
2004-10-01	40.3
2005-01-01	40.3
2005-04-01	39.7
2005-07-01	37.9
2005-10-01	39
2006-01-01	39
2006-04-01	38.7
2006-07-01	36.8
2006-10-01	38
2007-01-01	34.6
2007-04-01	33.6
2007-07-01	32.9
2007-10-01	34.1
2008-01-01	34.3
2008-04-01	34.0
2008-07-01	33.0
2008-10-01	34.6
2009-01-01	35.1
2009-04-01	34.4
2009-07-01	33.9
2009-10-01	35.4
2010-01-01	36.2
2010-04-01	35.0
2010-07-01	35.1
2010-10-01	35.6
2011-01-01	36.3
2011-04-01	35.1
2011-07-01	35.2
2011-10-01	35.6
2012-01-01	35.8
2012-04-01	35.3
2012-07-01	35.1
2012-10-01	35.7
2013-01-01	35.6
2013-04-01	34.1
2013-07-01	34.1
2013-10-01	34.9
2014-01-01	35.4
2014-04-01	35.1
2014-07-01	34.0
2014-10-01	34.9
2015-01-01	35.7
2015-04-01	34.7
2015-07-01	34.4
2015-10-01	34.5
2016-01-01	34.9
2016-04-01	33.1
2016-07-01	33.1
2016-10-01	33.8
2017-01-01	33.8
2017-04-01	33.5
2017-07-01	33.1
2017-10-01	33.1
2018-01-01	34.0
2018-04-01	32.6