Quarter	Percent
2000-04-01	36.2
2001-04-01	36.7
2002-04-01	36.6
2003-04-01	36.1
2004-04-01	35.6
2005-01-01	35.2
2005-04-01	35.9
2005-07-01	37.1
2005-10-01	36.1
2006-01-01	35.8
2006-04-01	36.4
2006-07-01	37.8
2006-10-01	36.6
2007-01-01	36.7
2007-04-01	37.3
2007-07-01	39.3
2007-10-01	37.7
2008-01-01	37.5
2008-04-01	37.4
2008-07-01	38.7
2008-10-01	36.6
2009-01-01	35.0
2009-04-01	34.7
2009-07-01	35.6
2009-10-01	34.0
2010-01-01	32.9
2010-04-01	33.1
2010-07-01	34.3
2010-10-01	33.3
2011-01-01	32.4
2011-04-01	32.8
2011-07-01	34.0
2011-10-01	32.7
2012-01-01	31.3
2012-04-01	31.6
2012-07-01	32.6
2012-10-01	31.3
2013-01-01	30.5
2013-04-01	31.0
2013-07-01	32.0
2013-10-01	30.8
2014-01-01	29.8
2014-04-01	30.3
2014-07-01	31.7
2014-10-01	30.7
2015-01-01	30.3
2015-04-01	30.4
2015-07-01	31.7
2015-10-01	31.0
2016-01-01	30.3
2016-04-01	31.1
2016-07-01	32.4
2016-10-01	31.7
2017-01-01	31.1
2017-04-01	31.8
2017-07-01	33.5
2017-10-01	32.8
2018-01-01	32.1
2018-04-01	32.8