Quarter	Percent
1999-04-01	26.5
2000-04-01	27.6
2001-04-01	24.9
2002-04-01	27.9
2003-01-01	30.7
2003-04-01	30.7
2003-07-01	30.7
2003-10-01	30.7
2004-01-01	30.9
2004-04-01	30.9
2004-07-01	30.9
2004-10-01	30.9
2005-01-01	32.4
2005-04-01	32.4
2005-07-01	32.4
2005-10-01	32.4
2006-01-01	33.6
2006-04-01	33.6
2006-07-01	33.6
2006-10-01	33.6
2007-01-01	31
2007-04-01	33.5
2007-07-01	35.4
2007-10-01	30.8
2008-01-01	32.5
2008-04-01	38.6
2008-07-01	37.3
2008-10-01	31.8
2009-01-01	38.6
2009-04-01	43.3
2009-07-01	38.2
2009-10-01	37.4
2010-01-01	39.1
2010-04-01	43.3
2010-07-01	39
2010-10-01	40.8
2011-01-01	40.9
2011-04-01	39
2011-07-01	43.3
2011-10-01	38.4
2012-01-01	42.7
2012-04-01	40.4
2012-07-01	43
2012-10-01	41.4
2013-01-01	41.7
2013-04-01	46.5
2013-07-01	41.5
2013-10-01	40.1
2014-01-01	43.3
2014-04-01	45.1
2014-07-01	44.4
2014-10-01	44.9
2015-01-01	44.0
2015-04-01	42.0
2015-07-01	36.0
2015-10-01	39.3
2016-01-01	42.9
2016-04-01	41.7
2016-07-01	39.9
2016-10-01	42.1
2017-01-01	42.2
2017-04-01	41.0
2017-07-01	40.4
2017-10-01	40.7
2018-01-01	41.0
2018-04-01	41.0