Quarter	Percent
1999-01-01	38
1999-04-01	37.7
1999-07-01	39.8
1999-10-01	40.5
2000-01-01	39.4
2000-04-01	39.4
2000-07-01	40.5
2000-10-01	39.5
2001-01-01	36.8
2001-04-01	37.2
2001-07-01	38.8
2001-10-01	37.9
2002-01-01	38.1
2002-04-01	38.5
2002-07-01	40.2
2002-10-01	39.2
2003-01-01	38.6
2003-04-01	39.2
2003-07-01	41
2003-10-01	39.4
2004-01-01	39.2
2004-04-01	39.8
2004-07-01	41.4
2004-10-01	39.6
2005-01-01	41
2005-04-01	43.4
2005-07-01	45.1
2005-10-01	42.6
2006-01-01	42.9
2006-04-01	44.5
2006-07-01	45.2
2006-10-01	43.3
2007-01-01	41.6
2007-04-01	43
2007-07-01	46.2
2007-10-01	42.7
2008-01-01	41.8
2008-04-01	44
2008-07-01	45.9
2008-10-01	43.3
2009-01-01	41.9
2009-04-01	41.6
2009-07-01	43.7
2009-10-01	39.7
2010-01-01	39.5
2010-04-01	40
2010-07-01	42.3
2010-10-01	39.2
2011-01-01	38.5
2011-04-01	39.4
2011-07-01	41.4
2011-10-01	37.6
2012-01-01	37.4
2012-04-01	38.2
2012-07-01	38.9
2012-10-01	36.1
2013-01-01	36
2013-04-01	35.3
2013-07-01	37.4
2013-10-01	34.9
2014-01-01	33.7
2014-04-01	33.2
2014-07-01	35
2014-10-01	34.1
2015-01-01	32.1
2015-04-01	33.7
2015-07-01	35.4
2015-10-01	31.5
2016-01-01	30.4
2016-04-01	31.5
2016-07-01	33.2
2016-10-01	30.0
2017-01-01	29.7
2017-04-01	31.1
2017-07-01	33.4
2017-10-01	31.7
2018-01-01	29.0
2018-04-01	30.7
2018-07-01	32.5