Quarter	Percent
1998-04-01	23.8
1999-01-01	26.3
1999-04-01	26.2
1999-07-01	25.7
1999-10-01	25.2
2000-01-01	26.7
2000-04-01	25.9
2000-07-01	28.3
2000-10-01	27.6
2001-01-01	25.7
2001-04-01	26
2001-07-01	25.8
2001-10-01	26.2
2002-01-01	27.8
2002-04-01	26.7
2002-07-01	28.3
2002-10-01	28
2003-01-01	27.3
2003-04-01	28.5
2003-07-01	29.3
2003-10-01	30.5
2004-01-01	30.5
2004-04-01	31.3
2004-07-01	31.8
2004-10-01	31.1
2005-01-01	32
2005-04-01	33.5
2005-07-01	34.2
2005-10-01	33.4
2006-01-01	32.7
2006-04-01	32.2
2006-07-01	33.9
2006-10-01	35.6
2007-01-01	36.1
2007-04-01	35.2
2007-07-01	35.7
2007-10-01	36.5
2008-01-01	36.1
2008-04-01	34.1
2008-07-01	37.7
2008-10-01	36.5
2009-01-01	35.9
2009-04-01	36.9
2009-07-01	37.8
2009-10-01	38
2010-01-01	38.5
2010-04-01	38.8
2010-07-01	39.6
2010-10-01	39.6
2011-01-01	38.9
2011-04-01	41.7
2011-07-01	40.5
2011-10-01	40.2
2012-01-01	40.2
2012-04-01	42
2012-07-01	42.2
2012-10-01	40.9
2013-01-01	43.1
2013-04-01	43.8
2013-07-01	45.5
2013-10-01	44
2014-01-01	43.4
2014-04-01	45.9
2014-07-01	44.5
2014-10-01	46.5
2015-01-01	45.7
2015-04-01	46.6
2015-07-01	47.2
2015-10-01	47.0
2016-01-01	46.5
2016-04-01	48.8
2016-07-01	48.3
2016-10-01	49.1
2017-01-01	49.8
2017-04-01	50.9
2017-07-01	51.8
2017-10-01	52.6
2018-01-01	52.0
2018-04-01	52.0