Quarter	Percent
1999-04-01	44.1
2000-04-01	42.9
2001-04-01	42.8
2002-04-01	43.2
2003-04-01	45.1
2004-04-01	47.5
2005-01-01	50.9
2005-04-01	51.8
2005-07-01	52.3
2005-10-01	53.4
2006-01-01	53.7
2006-04-01	54.5
2006-07-01	55.1
2006-10-01	56.4
2007-01-01	55.8
2007-04-01	57.6
2007-07-01	57.3
2007-10-01	58.1
2008-01-01	57.6
2008-04-01	59.1
2008-07-01	58.8
2008-10-01	59.4
2009-01-01	60
2009-04-01	61.4
2009-07-01	60.5
2009-10-01	61.9
2010-01-01	62.8
2010-04-01	62.4
2010-07-01	62.3
2010-10-01	62.8
2011-01-01	63.5
2011-04-01	64.2
2011-07-01	64.2
2011-10-01	64.6
2012-01-01	64.7
2012-04-01	65
2012-07-01	65.9
2012-10-01	66.1
2013-01-01	66.5
2013-04-01	67
2013-07-01	67.8
2013-10-01	68.5
2014-01-01	68.7
2014-04-01	68.8
2014-07-01	69.3
2014-10-01	69.5
2015-01-01	69.0
2015-04-01	68.9
2015-07-01	69.7
2015-10-01	70.1
2016-01-01	70.7
2016-04-01	71.2
2016-07-01	71.6
2016-10-01	71.9
2017-01-01	71.5
2017-04-01	72.6
2017-07-01	72.9
2017-10-01	73.4
2018-01-01	72.8
2018-04-01	73.1