Quarter	Percent
1999-04-01	35.1
2000-01-01	33.6
2000-04-01	33.9
2000-07-01	33.7
2000-10-01	33.5
2001-01-01	34.8
2001-04-01	33.7
2001-07-01	31.9
2001-10-01	34.4
2002-01-01	36.8
2002-04-01	35.9
2002-07-01	33.7
2002-10-01	33.5
2003-01-01	34.3
2003-04-01	33.8
2003-07-01	32.9
2003-10-01	32.4
2004-01-01	32.5
2004-04-01	32.5
2004-07-01	33.1
2004-10-01	33.8
2005-01-01	32.3
2005-04-01	31
2005-07-01	32.8
2005-10-01	32.2
2006-01-01	30.9
2006-04-01	28.7
2006-07-01	30.9
2006-10-01	31
2007-01-01	31.7
2007-04-01	30.2
2007-07-01	30.5
2007-10-01	31.8
2008-01-01	31.4
2008-04-01	31.1
2008-07-01	28.4
2008-10-01	27.9
2009-01-01	28.9
2009-04-01	29.7
2009-07-01	29.5
2009-10-01	29.6
2010-01-01	28.2
2010-04-01	28.5
2010-07-01	29.1
2010-10-01	29.8
2011-01-01	29.8
2011-04-01	28.3
2011-07-01	27
2011-10-01	29
2012-01-01	28.3
2012-04-01	28.1
2012-07-01	28.1
2012-10-01	29.9
2013-01-01	28.3
2013-04-01	27.6
2013-07-01	28.9
2013-10-01	28.1
2014-01-01	30.1
2014-04-01	28.9
2014-07-01	27.4
2014-10-01	28.3
2015-01-01	28.9
2015-04-01	27.1
2015-07-01	25.6
2015-10-01	26.3
2016-01-01	28.2
2016-04-01	25.9
2016-07-01	25.7
2016-10-01	27.2
2017-01-01	25.7
2017-04-01	25.4
2017-07-01	25.3
2017-10-01	23.4
2018-01-01	24.3
2018-04-01	25.1