Quarter	Percent
2000-04-01	27.4
2001-04-01	28.2
2002-04-01	28.9
2003-04-01	30.6
2004-04-01	31.4
2005-01-01	32.9
2005-04-01	33.7
2005-07-01	33.7
2005-10-01	34.1
2006-01-01	34.1
2006-04-01	34.7
2006-07-01	35.4
2006-10-01	35.2
2007-01-01	34.9
2007-04-01	36.1
2007-07-01	36.1
2007-10-01	36.1
2008-01-01	35.9
2008-04-01	36.9
2008-07-01	37.1
2008-10-01	37.0
2009-01-01	37.1
2009-04-01	38.1
2009-07-01	37.8
2009-10-01	37.8
2010-01-01	38.0
2010-04-01	38.4
2010-07-01	38.9
2010-10-01	38.7
2011-01-01	39.2
2011-04-01	40.0
2011-07-01	40.4
2011-10-01	40.4
2012-01-01	40.8
2012-04-01	41.6
2012-07-01	42.2
2012-10-01	42.1
2013-01-01	42.2
2013-04-01	43.1
2013-07-01	43.8
2013-10-01	44.1
2014-01-01	44.2
2014-04-01	45.0
2014-07-01	45.5
2014-10-01	45.9
2015-01-01	45.9
2015-04-01	46.8
2015-07-01	47.2
2015-10-01	47.5
2016-01-01	47.9
2016-04-01	49.0
2016-07-01	49.2
2016-10-01	49.5
2017-01-01	49.8
2017-04-01	51.0
2017-07-01	51.2
2017-10-01	51.4
2018-01-01	51.7
2018-04-01	52.3