Quarter	Percent
1999-04-01	60.2
2000-04-01	63
2001-04-01	63.8
2002-04-01	64.5
2003-01-01	63.8
2003-04-01	63.8
2003-07-01	63.8
2003-10-01	63.8
2004-01-01	66.2
2004-04-01	66.2
2004-07-01	66.2
2004-10-01	66.2
2005-01-01	68.4
2005-04-01	68.4
2005-07-01	68.4
2005-10-01	68.4
2006-01-01	69.5
2006-04-01	69.5
2006-07-01	69.5
2006-10-01	69.5
2007-01-01	71.8
2007-04-01	70.4
2007-07-01	70.7
2007-10-01	73.9
2008-01-01	68.7
2008-04-01	69.7
2008-07-01	69.5
2008-10-01	70.3
2009-01-01	73.1
2009-04-01	70.3
2009-07-01	72.2
2009-10-01	70
2010-01-01	73.8
2010-04-01	71.5
2010-07-01	72.7
2010-10-01	72.3
2011-01-01	73.6
2011-04-01	72.4
2011-07-01	72.2
2011-10-01	73.2
2012-01-01	73.8
2012-04-01	74.7
2012-07-01	75.5
2012-10-01	75.9
2013-01-01	76.9
2013-04-01	74.7
2013-07-01	75.6
2013-10-01	74.8
2014-01-01	76.4
2014-04-01	77.1
2014-07-01	75.5
2014-10-01	78.2
2015-01-01	75.1
2015-04-01	77.4
2015-07-01	73.9
2015-10-01	76.6
2016-01-01	76.5
2016-04-01	75.4
2016-07-01	75.2
2016-10-01	78.3
2017-01-01	79.4
2017-04-01	80.3
2017-07-01	80.8
2017-10-01	78.7
2018-01-01	80.5
2018-04-01	79.3