Quarter	Percent
1998-04-01	32.6
1999-04-01	31
2000-04-01	31.6
2001-04-01	32.2
2002-04-01	30.7
2003-04-01	30.6
2004-04-01	32.9
2005-04-01	34.3
2006-04-01	31.4
2007-04-01	32.6
2008-04-01	32.9
2009-04-01	32.7
2010-01-01	32.0
2010-04-01	33.5
2010-07-01	29.5
2010-10-01	32.6
2011-01-01	32.0
2011-04-01	33.2
2011-07-01	29.8
2011-10-01	30.8
2012-01-01	32.8
2012-04-01	34.8
2012-07-01	30.0
2012-10-01	32.1
2013-01-01	31.6
2013-04-01	33.8
2013-07-01	31.5
2013-10-01	31.0
2014-01-01	32.8
2014-04-01	33.6
2014-07-01	31.2
2014-10-01	30.8
2015-01-01	33.6
2015-04-01	34.4
2015-07-01	31.4
2015-10-01	30.6
2016-01-01	31.7
2016-04-01	34.2
2016-07-01	30.9
2016-10-01	29.9
2017-01-01	31.6
2017-04-01	33.4
2017-07-01	29.1
2017-10-01	31.2
2018-01-01	33.2
2018-04-01	34.4