Quarter	Percent
1999-01-01	11.6
1999-04-01	11.3
1999-07-01	10.7
1999-10-01	10.6
2000-01-01	11.4
2000-04-01	11.1
2000-07-01	10.1
2000-10-01	10.3
2001-01-01	10.9
2001-04-01	11.1
2001-07-01	11.4
2001-10-01	10.6
2002-01-01	11
2002-04-01	10.6
2002-07-01	11.2
2002-10-01	11.6
2003-01-01	11.4
2003-04-01	12.2
2003-07-01	12.9
2003-10-01	13.2
2004-01-01	13
2004-04-01	14.4
2004-07-01	15.7
2004-10-01	16.1
2005-01-01	16.5
2005-04-01	17.8
2005-07-01	18.6
2005-10-01	19.5
2006-01-01	19.4
2006-04-01	21
2006-07-01	21.3
2006-10-01	21.9
2007-01-01	22.1
2007-04-01	23.2
2007-07-01	23.3
2007-10-01	24.4
2008-01-01	25.2
2008-04-01	25.5
2008-07-01	27.6
2008-10-01	27.3
2009-01-01	27.4
2009-04-01	29
2009-07-01	29.9
2009-10-01	29.5
2010-01-01	31.5
2010-04-01	32.4
2010-07-01	32.5
2010-10-01	32.6
2011-01-01	32.6
2011-04-01	34.1
2011-07-01	35.4
2011-10-01	36.2
2012-01-01	37.1
2012-04-01	38
2012-07-01	38.3
2012-10-01	38.6
2013-01-01	40.1
2013-04-01	40.2
2013-07-01	40.3
2013-10-01	41.2
2014-01-01	40.5
2014-04-01	41.4
2014-07-01	42.7
2014-10-01	44
2015-01-01	44.9
2015-04-01	44.9
2015-07-01	46.1
2015-10-01	47.3
2016-01-01	46.3
2016-04-01	48.3
2016-07-01	48.6
2016-10-01	49.6
2017-01-01	51.2
2017-04-01	53.3
2017-07-01	53.1
2017-10-01	54.6
2018-01-01	53.3
2018-04-01	52.8