Quarter	Percent
1999-01-01	62.5
1999-04-01	63
1999-07-01	63.1
1999-10-01	62
2000-01-01	62
2000-04-01	63.1
2000-07-01	64.1
2000-10-01	62.7
2001-01-01	62.7
2001-04-01	62.5
2001-07-01	64.3
2001-10-01	63.5
2002-01-01	63.5
2002-04-01	63.9
2002-07-01	63.1
2002-10-01	61.4
2003-01-01	61.9
2003-04-01	62.1
2003-07-01	61.9
2003-10-01	62.6
2004-01-01	63.7
2004-04-01	65.6
2004-07-01	66.3
2004-10-01	64.3
2005-01-01	65.4
2005-04-01	65.8
2005-07-01	66.6
2005-10-01	66.6
2006-01-01	67
2006-04-01	67.9
2006-07-01	66.6
2006-10-01	65.5
2007-01-01	65.7
2007-04-01	67.2
2007-07-01	67.3
2007-10-01	66.1
2008-01-01	66.4
2008-04-01	67
2008-07-01	68.5
2008-10-01	68.2
2009-01-01	67
2009-04-01	67.5
2009-07-01	68.9
2009-10-01	68
2010-01-01	67.2
2010-04-01	68.3
2010-07-01	66.8
2010-10-01	67.2
2011-01-01	65.7
2011-04-01	66.1
2011-07-01	66.6
2011-10-01	67.4
2012-01-01	67.3
2012-04-01	66.2
2012-07-01	67.2
2012-10-01	66.9
2013-01-01	66.3
2013-04-01	66.6
2013-07-01	67.5
2013-10-01	66
2014-01-01	66.9
2014-04-01	67.9
2014-07-01	67.6
2014-10-01	66.6
2015-01-01	66.5
2015-04-01	68.6
2015-07-01	69.1
2015-10-01	67.6
2016-01-01	67.5
2016-04-01	69.1
2016-07-01	68.2
2016-10-01	69.6
2017-01-01	70.3
2017-04-01	70.5
2017-07-01	72.2
2017-10-01	71.9
2018-01-01	71.2
2018-04-01	71.5