Quarter	Percent
1999-04-01	73.6
1999-07-01	76.6
1999-10-01	75.2
2000-01-01	75.2
2000-04-01	75.7
2000-07-01	78.1
2000-10-01	76.3
2001-01-01	76.1
2001-04-01	76.2
2001-07-01	78.2
2001-10-01	76.1
2002-01-01	75
2002-04-01	75
2002-07-01	76.6
2002-10-01	75.1
2003-01-01	74.6
2003-04-01	74.7
2003-07-01	76.1
2003-10-01	75.4
2004-01-01	75.5
2004-04-01	75.2
2004-07-01	77.1
2004-10-01	76
2005-01-01	76
2005-04-01	76.2
2005-07-01	78.2
2005-10-01	77
2006-01-01	77.3
2006-04-01	77.4
2006-07-01	78.8
2006-10-01	77.9
2007-01-01	80.4
2007-04-01	80.4
2007-07-01	81.2
2007-10-01	79.6
2008-01-01	78.3
2008-04-01	78.0
2008-07-01	77.4
2008-10-01	74.4
2009-01-01	70.0
2009-04-01	68.6
2009-07-01	67.8
2009-10-01	66.4
2010-01-01	65.0
2010-04-01	65.3
2010-07-01	65.4
2010-10-01	63.9
2011-01-01	63.3
2011-04-01	64.0
2011-07-01	64.1
2011-10-01	64.0
2012-01-01	62.8
2012-04-01	63.4
2012-07-01	64.3
2012-10-01	64.2
2013-01-01	64.6
2013-04-01	65.8
2013-07-01	67.3
2013-10-01	67.9
2014-01-01	67.0
2014-04-01	67.7
2014-07-01	69.1
2014-10-01	69.4
2015-01-01	69.1
2015-04-01	70.2
2015-07-01	71.1
2015-10-01	70.5
2016-01-01	70.2
2016-04-01	71.6
2016-07-01	72.9
2016-10-01	72.7
2017-01-01	72.3
2017-04-01	72.6
2017-07-01	73.7
2017-10-01	73.5
2018-01-01	73.6
2018-04-01	73.8