Quarter	Percent
1999-01-01	10.3
1999-04-01	11.3
1999-07-01	11.9
1999-10-01	12.1
2000-01-01	12.1
2000-04-01	13.2
2000-07-01	14
2000-10-01	14.7
2001-01-01	14.3
2001-04-01	14.4
2001-07-01	15.7
2001-10-01	15.9
2002-01-01	16.6
2002-04-01	17.3
2002-07-01	18.1
2002-10-01	19.8
2003-01-01	20.8
2003-04-01	21.8
2003-07-01	22.8
2003-10-01	24
2004-01-01	24.8
2004-04-01	25.1
2004-07-01	26.1
2004-10-01	27.1
2005-01-01	26.8
2005-04-01	27.7
2005-07-01	28
2005-10-01	28.2
2006-01-01	27.7
2006-04-01	27.9
2006-07-01	27.6
2006-10-01	27.5
2007-01-01	27
2007-04-01	27.7
2007-07-01	26.5
2007-10-01	26.3
2008-01-01	26.2
2008-04-01	26
2008-07-01	27
2008-10-01	27.3
2009-01-01	27.3
2009-04-01	27.7
2009-07-01	27.8
2009-10-01	29.5
2010-01-01	29.9
2010-04-01	31
2010-07-01	32.4
2010-10-01	33.4
2011-01-01	34.1
2011-04-01	34.8
2011-07-01	35.1
2011-10-01	35
2012-01-01	34.4
2012-04-01	35
2012-07-01	34.9
2012-10-01	33.7
2013-01-01	33.4
2013-04-01	34.5
2013-07-01	35.1
2013-10-01	35.9
2014-01-01	36.1
2014-04-01	37.3
2014-07-01	38
2014-10-01	38.1
2015-01-01	38.6
2015-04-01	39.7
2015-07-01	40.7
2015-10-01	40.6
2016-01-01	42.0
2016-04-01	43.5
2016-07-01	44.1
2016-10-01	44.3
2017-01-01	43.2
2017-04-01	44.1
2017-07-01	44.9
2017-10-01	45.0
2018-01-01	46.0
2018-04-01	45.7