Quarter	Percent
1999-01-01	63.6
2000-01-01	60.4
2000-04-01	61.2
2000-07-01	61.9
2000-10-01	61.4
2001-01-01	59.3
2001-04-01	59.2
2001-07-01	59.6
2001-10-01	58.5
2002-01-01	56.5
2002-04-01	57
2002-07-01	57.4
2002-10-01	56.7
2003-01-01	55.2
2003-04-01	56.4
2003-07-01	57.3
2003-10-01	57
2004-01-01	55.7
2004-04-01	56.8
2004-07-01	57.8
2004-10-01	58.4
2005-01-01	57.5
2005-04-01	58.2
2005-07-01	59.9
2005-10-01	59.8
2006-01-01	58.5
2006-04-01	60.2
2006-07-01	62.2
2006-10-01	62.6
2007-01-01	62
2007-04-01	63.4
2007-07-01	64.3
2007-10-01	64.9
2008-01-01	64.9
2008-04-01	66
2008-07-01	67.2
2008-10-01	67.1
2009-01-01	65.7
2009-04-01	66
2009-07-01	66.9
2009-10-01	65.9
2010-01-01	64
2010-04-01	65.2
2010-07-01	66.2
2010-10-01	65.9
2011-01-01	64.7
2011-04-01	66
2011-07-01	66.9
2011-10-01	66.3
2012-01-01	65.1
2012-04-01	66.4
2012-07-01	67.1
2012-10-01	66.6
2013-01-01	65.2
2013-04-01	66.5
2013-07-01	67.5
2013-10-01	67.2
2014-01-01	66.3
2014-04-01	67.9
2014-07-01	69.4
2014-10-01	69.2
2015-01-01	68.1
2015-04-01	68.7
2015-07-01	70.1
2015-10-01	70.1
2016-01-01	69.9
2016-04-01	70.6
2016-07-01	71.6
2016-10-01	71.8
2017-01-01	71.8
2017-04-01	72.5
2017-07-01	73.5
2017-10-01	73.4
2018-01-01	73.1
2018-04-01	74.0