Quarter	Percent
1998-04-01	32.9
1998-10-01	33.6
1999-04-01	32.4
1999-10-01	31.9
2000-04-01	30.3
2000-10-01	28.1
2001-04-01	28.3
2001-10-01	28.1
2002-01-01	30.6
2002-04-01	28.3
2002-07-01	33.2
2002-10-01	31.0
2003-01-01	30.0
2003-04-01	30.9
2003-07-01	30.6
2003-10-01	30.8
2004-01-01	30.0
2004-04-01	28.9
2004-07-01	31.3
2004-10-01	31.4
2005-01-01	30.7
2005-04-01	30.6
2005-07-01	34.9
2005-10-01	32.7
2006-01-01	33.3
2006-04-01	32.1
2006-07-01	39.6
2006-10-01	36.2
2007-01-01	36.1
2007-04-01	37.7
2007-07-01	39.0
2007-10-01	39.7
2008-01-01	39.6
2008-04-01	38.6
2008-07-01	39.1
2008-10-01	30.8
2009-01-01	29.3
2009-04-01	28.0
2009-07-01	28.1
2009-10-01	24.6
2010-01-01	24.5
2010-04-01	24.9
2010-07-01	27.6
2010-10-01	24.6
2011-01-01	24.4
2011-04-01	25.3
2011-07-01	26.4
2011-10-01	27.2
2012-01-01	27.3
2012-04-01	28.0
2012-07-01	28.1
2012-10-01	31.4
2013-01-01	29.7
2013-04-01	29.6
2013-07-01	30.2
2013-10-01	31.4
2014-01-01	31.8
2014-04-01	30.9
2014-07-01	33.0
2014-10-01	34.3
2015-01-01	34.0
2015-04-01	34.6
2015-07-01	33.5
2015-10-01	36.1
2016-01-01	34.2
2016-04-01	33.0
2016-07-01	32.5
2016-10-01	31.5
2017-01-01	30.6
2017-04-01	35.8
2017-07-01	34.9
2017-10-01	30.6
2018-01-01	31.7
2018-04-01	33.8