Quarter	Percent
1998-04-01	22.5
1999-01-01	25.1
1999-04-01	24.7
1999-07-01	24.3
1999-10-01	24.2
2000-01-01	25.8
2000-04-01	25
2000-07-01	27.6
2000-10-01	26.8
2001-01-01	24.7
2001-04-01	25.2
2001-07-01	25.3
2001-10-01	25.2
2002-01-01	26.6
2002-04-01	25.8
2002-07-01	27
2002-10-01	26.9
2003-01-01	26.6
2003-04-01	28.1
2003-07-01	28.5
2003-10-01	29.3
2004-01-01	29.2
2004-04-01	30.1
2004-07-01	30.7
2004-10-01	30
2005-01-01	30.5
2005-04-01	32.1
2005-07-01	32.9
2005-10-01	31.7
2006-01-01	31.3
2006-04-01	30.4
2006-07-01	32.2
2006-10-01	34
2007-01-01	34
2007-04-01	33.8
2007-07-01	34.5
2007-10-01	35.2
2008-01-01	34.6
2008-04-01	32.8
2008-07-01	35.6
2008-10-01	35
2009-01-01	34
2009-04-01	34.8
2009-07-01	35.9
2009-10-01	36.2
2010-01-01	37.1
2010-04-01	36.9
2010-07-01	37.5
2010-10-01	37.9
2011-01-01	37.1
2011-04-01	40.1
2011-07-01	38.7
2011-10-01	38.9
2012-01-01	38.5
2012-04-01	40.3
2012-07-01	40.2
2012-10-01	39
2013-01-01	40.5
2013-04-01	41.6
2013-07-01	42.9
2013-10-01	41.9
2014-01-01	41
2014-04-01	43.7
2014-07-01	42.4
2014-10-01	43.6
2015-01-01	42.9
2015-04-01	43.8
2015-07-01	44.7
2015-10-01	44.7
2016-01-01	44.0
2016-04-01	45.6
2016-07-01	45.6
2016-10-01	46.5
2017-01-01	46.2
2017-04-01	47.7
2017-07-01	49.2
2017-10-01	49.8
2018-01-01	49.6
2018-04-01	49.8