Quarter	Percent
1999-04-01	31.9
2000-04-01	30.6
2001-04-01	32.1
2002-04-01	31.2
2003-01-01	29.7
2003-04-01	29.7
2003-07-01	29.7
2003-10-01	29.7
2004-01-01	26.4
2004-04-01	26.4
2004-07-01	26.4
2004-10-01	26.4
2005-01-01	25.5
2005-04-01	25.5
2005-07-01	25.5
2005-10-01	25.5
2006-01-01	25
2006-04-01	25
2006-07-01	25
2006-10-01	25
2007-01-01	21
2007-04-01	16.8
2007-07-01	25.8
2007-10-01	25.6
2008-01-01	22.5
2008-04-01	25.3
2008-07-01	29.2
2008-10-01	31.5
2009-01-01	24.8
2009-04-01	30.8
2009-07-01	29.8
2009-10-01	32.2
2010-01-01	19.5
2010-04-01	22.5
2010-07-01	25.5
2010-10-01	23.1
2011-01-01	25.9
2011-04-01	19.3
2011-07-01	24.9
2011-10-01	23.4
2012-01-01	21.9
2012-04-01	19.8
2012-07-01	28.3
2012-10-01	28.5
2013-01-01	21.8
2013-04-01	22.6
2013-07-01	17.7
2013-10-01	25
2014-01-01	28.7
2014-04-01	19.9
2014-07-01	22.8
2014-10-01	20.6
2015-01-01	35.3
2015-04-01	31.9
2015-07-01	39.3
2015-10-01	30.1
2016-01-01	26.9
2016-04-01	31.1
2016-07-01	38.0
2016-10-01	28.2
2017-01-01	29.7
2017-04-01	22.8
2017-07-01	32.1
2017-10-01	28.5
2018-01-01	29.8
2018-04-01	27.0