Quarter	Percent
1999-04-01	25.7
1999-07-01	26.1
1999-10-01	26.5
2000-01-01	26.7
2000-04-01	27.1
2000-07-01	27.1
2000-10-01	27.8
2001-01-01	28.3
2001-04-01	28.4
2001-07-01	29.1
2001-10-01	29.2
2002-01-01	29.8
2002-04-01	30.7
2002-07-01	31.1
2002-10-01	31.6
2003-01-01	32.2
2003-04-01	33.4
2003-07-01	33.5
2003-10-01	33.2
2004-01-01	33.5
2004-04-01	34
2004-07-01	32.8
2004-10-01	34.6
2005-01-01	35.8
2005-04-01	37.4
2005-07-01	37.4
2005-10-01	38.5
2006-01-01	38.7
2006-04-01	40
2006-07-01	38.8
2006-10-01	38.6
2007-01-01	39.5
2007-04-01	40.1
2007-07-01	39.6
2007-10-01	40.7
2008-01-01	40.7
2008-04-01	41.6
2008-07-01	42.0
2008-10-01	41.2
2009-01-01	41.7
2009-04-01	42.1
2009-07-01	42.0
2009-10-01	41.3
2010-01-01	41.7
2010-04-01	43.8
2010-07-01	43.6
2010-10-01	42.1
2011-01-01	43.4
2011-04-01	44.2
2011-07-01	43.0
2011-10-01	43.7
2012-01-01	43.2
2012-04-01	43.9
2012-07-01	42.8
2012-10-01	43.5
2013-01-01	42.9
2013-04-01	43.6
2013-07-01	43.7
2013-10-01	45.3
2014-01-01	44.5
2014-04-01	45.3
2014-07-01	45.2
2014-10-01	45.7
2015-01-01	46.3
2015-04-01	46.4
2015-07-01	46.7
2015-10-01	48.0
2016-01-01	49.4
2016-04-01	49.0
2016-07-01	48.5
2016-10-01	49.6
2017-01-01	50.2
2017-04-01	51.0
2017-07-01	49.7
2017-10-01	51.6
2018-01-01	51.2
2018-04-01	52.0