Quarter	Percent
1999-01-01	52
1999-04-01	52.1
1999-07-01	52.3
1999-10-01	52.3
2000-01-01	53
2000-04-01	54.7
2000-07-01	55.8
2000-10-01	56.3
2001-01-01	57.1
2001-04-01	57.8
2001-07-01	57.9
2001-10-01	58.1
2002-01-01	57.8
2002-04-01	58.4
2002-07-01	58.5
2002-10-01	59.1
2003-01-01	59
2003-04-01	59.2
2003-07-01	58.7
2003-10-01	59.3
2004-01-01	58.7
2004-04-01	58.1
2004-07-01	58.5
2004-10-01	58.6
2005-01-01	58.8
2005-04-01	59.1
2005-07-01	59.3
2005-10-01	60.2
2006-01-01	60.1
2006-04-01	60.4
2006-07-01	60.2
2006-10-01	59.9
2007-01-01	59
2007-04-01	59.7
2007-07-01	60
2007-10-01	59.9
2008-01-01	60.4
2008-04-01	61
2008-07-01	60.7
2008-10-01	60
2009-01-01	58
2009-04-01	57
2009-07-01	55.6
2009-10-01	55
2010-01-01	54.5
2010-04-01	54.7
2010-07-01	54.7
2010-10-01	54
2011-01-01	54.4
2011-04-01	54.2
2011-07-01	53.4
2011-10-01	53
2012-01-01	52.1
2012-04-01	52.7
2012-07-01	52.2
2012-10-01	51.4
2013-01-01	50.1
2013-04-01	50.4
2013-07-01	51
2013-10-01	50.5
2014-01-01	49.7
2014-04-01	51
2014-07-01	51.8
2014-10-01	52.1
2015-01-01	52.8
2015-04-01	54.0
2015-07-01	54.6
2015-10-01	54.6
2016-01-01	55.3
2016-04-01	55.4
2016-07-01	56.2
2016-10-01	55.9
2017-01-01	56.4
2017-04-01	57.8
2017-07-01	58.7
2017-10-01	58.3
2018-01-01	58.3
2018-04-01	59.4
2018-07-01	60.6