Quarter	Percent
1998-04-01	32.0
1999-04-01	32.1
2000-04-01	32.6
2001-04-01	32.2
2002-04-01	32.3
2003-04-01	32.2
2004-04-01	32.7
2005-04-01	33
2006-04-01	32.6
2007-04-01	32.4
2008-04-01	31.8
2009-04-01	31.8
2010-01-01	33.2
2010-04-01	33.0
2010-07-01	32.7
2010-10-01	33.1
2011-01-01	32.7
2011-04-01	32.8
2011-07-01	32.5
2011-10-01	32.2
2012-01-01	32.8
2012-04-01	32.8
2012-07-01	32.0
2012-10-01	32.4
2013-01-01	32.5
2013-04-01	32.7
2013-07-01	32.4
2013-10-01	32.3
2014-01-01	32.5
2014-04-01	32.2
2014-07-01	32.1
2014-10-01	31.5
2015-01-01	31.9
2015-04-01	32.1
2015-07-01	31.9
2015-10-01	31.4
2016-01-01	31.4
2016-04-01	31.7
2016-07-01	31.4
2016-10-01	31.2
2017-01-01	31.6
2017-04-01	31.7
2017-07-01	31.4
2017-10-01	31.4
2018-01-01	31.6
2018-04-01	31.6