Quarter	Percent
1999-04-01	34
2000-04-01	34
2001-04-01	34.5
2002-04-01	34.7
2003-01-01	30.4
2003-04-01	30.4
2003-07-01	30.4
2003-10-01	30.4
2004-01-01	28
2004-04-01	28
2004-07-01	28
2004-10-01	28
2005-01-01	28.8
2005-04-01	28.8
2005-07-01	28.8
2005-10-01	28.8
2006-01-01	27.8
2006-04-01	27.8
2006-07-01	27.8
2006-10-01	27.8
2007-01-01	26.6
2007-04-01	26.3
2007-07-01	27.4
2007-10-01	25.7
2008-01-01	26.5
2008-04-01	30.3
2008-07-01	28.5
2008-10-01	30.7
2009-01-01	26.9
2009-04-01	34
2009-07-01	32.8
2009-10-01	35.3
2010-01-01	22.9
2010-04-01	23.3
2010-07-01	27.5
2010-10-01	25.3
2011-01-01	27.1
2011-04-01	21.2
2011-07-01	26.5
2011-10-01	24.7
2012-01-01	24.7
2012-04-01	22.4
2012-07-01	29.3
2012-10-01	30.6
2013-01-01	22.8
2013-04-01	25.6
2013-07-01	24.8
2013-10-01	30.5
2014-01-01	29.4
2014-04-01	23.2
2014-07-01	26.3
2014-10-01	26.4
2015-01-01	34.8
2015-04-01	33.0
2015-07-01	40.7
2015-10-01	32.1
2016-01-01	27.2
2016-04-01	30.0
2016-07-01	34.6
2016-10-01	31.0
2017-01-01	30.5
2017-04-01	27.4
2017-07-01	33.8
2017-10-01	30.2
2018-01-01	31.9
2018-04-01	28.3