Quarter	Percent
1999-04-01	71
2000-04-01	77.4
2001-04-01	76
2002-04-01	68.3
2003-01-01	63.1
2003-04-01	67
2003-07-01	77.6
2003-10-01	57.5
2004-01-01	59.3
2004-04-01	70.1
2004-07-01	74.7
2004-10-01	64
2005-01-01	69.5
2005-04-01	76.8
2005-07-01	75.5
2005-10-01	71.6
2006-01-01	70.7
2006-04-01	77.9
2006-07-01	79.2
2006-10-01	68.7
2007-01-01	71
2007-04-01	78.5
2007-07-01	77.3
2007-10-01	71.2
2008-01-01	70.3
2008-04-01	75.7
2008-07-01	77.5
2008-10-01	70.5
2009-01-01	62.5
2009-04-01	68.3
2009-07-01	70.9
2009-10-01	64.3
2010-01-01	59.9
2010-04-01	71.9
2010-07-01	69.2
2010-10-01	60.4
2011-01-01	61.6
2011-04-01	75.7
2011-07-01	68.1
2011-10-01	60.8
2012-01-01	61.3
2012-04-01	67.7
2012-07-01	74.8
2012-10-01	69.7
2013-01-01	68
2013-04-01	77.6
2013-07-01	78.8
2013-10-01	76.1
2014-01-01	71.4
2014-04-01	75.9
2014-07-01	77.5
2014-10-01	69.6
2015-01-01	70.5
2015-04-01	78.1
2015-07-01	80.0
2015-10-01	77.4
2016-01-01	71.9
2016-04-01	83.9
2016-07-01	82.6
2016-10-01	74.2
2017-01-01	76.6
2017-04-01	82.5
2017-07-01	75.1
2017-10-01	71.9
2018-01-01	73.6
2018-04-01	80.3