Quarter	Percent
1999-04-01	35.3
2000-01-01	39.2
2000-04-01	34
2000-07-01	32.1
2000-10-01	37.2
2001-01-01	40.9
2001-04-01	33.9
2001-07-01	34.4
2001-10-01	37.7
2002-01-01	38.4
2002-04-01	34.5
2002-07-01	33.3
2002-10-01	37.7
2003-01-01	40.9
2003-04-01	36.3
2003-07-01	35.6
2003-10-01	39.3
2004-01-01	41.9
2004-04-01	37
2004-07-01	35.4
2004-10-01	39.3
2005-01-01	43.9
2005-04-01	38.3
2005-07-01	36.3
2005-10-01	40.1
2006-01-01	44.6
2006-04-01	41.1
2006-07-01	39.6
2006-10-01	44.9
2007-01-01	44.3
2007-04-01	40.3
2007-07-01	38.9
2007-10-01	41.3
2008-01-01	38.7
2008-04-01	35.7
2008-07-01	36.7
2008-10-01	41
2009-01-01	42.4
2009-04-01	39.5
2009-07-01	41.3
2009-10-01	45.2
2010-01-01	44.4
2010-04-01	40.9
2010-07-01	43.2
2010-10-01	44.5
2011-01-01	46.1
2011-04-01	44.1
2011-07-01	42.5
2011-10-01	44.8
2012-01-01	44.9
2012-04-01	41.5
2012-07-01	41.6
2012-10-01	43.9
2013-01-01	42.8
2013-04-01	42.2
2013-07-01	42
2013-10-01	44.9
2014-01-01	46.8
2014-04-01	44.6
2014-07-01	44.6
2014-10-01	46.4
2015-01-01	46.0
2015-04-01	42.0
2015-07-01	41.9
2015-10-01	46.5
2016-01-01	45.6
2016-04-01	44.9
2016-07-01	43.6
2016-10-01	47.6
2017-01-01	48.1
2017-04-01	45.3
2017-07-01	44.4
2017-10-01	47.2
2018-01-01	47.9
2018-04-01	44.4