Quarter	Percent
1999-01-01	39.1
1999-04-01	41.9
1999-07-01	47.8
1999-10-01	43.9
2000-01-01	39.1
2000-04-01	40.7
2000-07-01	45.3
2000-10-01	41.8
2001-01-01	38.5
2001-04-01	40.1
2001-07-01	43.8
2001-10-01	39.6
2002-01-01	42
2002-04-01	40.2
2002-07-01	42.1
2002-10-01	37.5
2003-01-01	38.4
2003-04-01	38.3
2003-07-01	40.5
2003-10-01	42.3
2004-01-01	43
2004-04-01	43.1
2004-07-01	49.1
2004-10-01	45.2
2005-01-01	45.2
2005-04-01	40.9
2005-07-01	47.8
2005-10-01	44.2
2006-01-01	41.7
2006-04-01	44.5
2006-07-01	49.3
2006-10-01	42.1
2007-01-01	44.9
2007-04-01	46.1
2007-07-01	52.9
2007-10-01	46.7
2008-01-01	43.9
2008-04-01	46.2
2008-07-01	54.5
2008-10-01	46
2009-01-01	41.1
2009-04-01	43.4
2009-07-01	51.2
2009-10-01	45.6
2010-01-01	43.9
2010-04-01	42.2
2010-07-01	46.9
2010-10-01	44.5
2011-01-01	40.3
2011-04-01	40.1
2011-07-01	46.3
2011-10-01	41.1
2012-01-01	35.9
2012-04-01	37.1
2012-07-01	41
2012-10-01	38.7
2013-01-01	34.9
2013-04-01	37.6
2013-07-01	39.9
2013-10-01	36.1
2014-01-01	34.1
2014-04-01	35.4
2014-07-01	38.5
2014-10-01	38.3
2015-01-01	36.5
2015-04-01	37.5
2015-07-01	42.3
2015-10-01	39.3
2016-01-01	35.8
2016-04-01	34.3
2016-07-01	39.5
2016-10-01	37.7
2017-01-01	39.4
2017-04-01	42.7
2017-07-01	48.3
2017-10-01	41.0
2018-01-01	40.4
2018-04-01	45.1