Quarter	Percent
1999-01-01	34.4
1999-04-01	35.7
1999-07-01	37.9
1999-10-01	36.9
2000-01-01	36.3
2000-04-01	37.5
2000-07-01	40
2000-10-01	39
2001-01-01	38.7
2001-04-01	39.6
2001-07-01	42
2001-10-01	40.5
2002-01-01	39.6
2002-04-01	40.4
2002-07-01	41.2
2002-10-01	39.1
2003-01-01	38.8
2003-04-01	39.9
2003-07-01	41.9
2003-10-01	40.2
2004-01-01	40
2004-04-01	40.1
2004-07-01	42.6
2004-10-01	41.1
2005-01-01	42.1
2005-04-01	43
2005-07-01	46.5
2005-10-01	43.5
2006-01-01	42.3
2006-04-01	43.7
2006-07-01	47
2006-10-01	44.4
2007-01-01	43.9
2007-04-01	44.5
2007-07-01	46.1
2007-10-01	42.4
2008-01-01	40.9
2008-04-01	39.8
2008-07-01	41.3
2008-10-01	35.3
2009-01-01	31.2
2009-04-01	29.2
2009-07-01	30
2009-10-01	27.1
2010-01-01	25.4
2010-04-01	26
2010-07-01	26.9
2010-10-01	24
2011-01-01	22.2
2011-04-01	22.1
2011-07-01	23.7
2011-10-01	20.3
2012-01-01	18.3
2012-04-01	18.5
2012-07-01	20.1
2012-10-01	17.2
2013-01-01	16.2
2013-04-01	17.3
2013-07-01	18.9
2013-10-01	17
2014-01-01	16.4
2014-04-01	17.2
2014-07-01	18.6
2014-10-01	17.5
2015-01-01	16.9
2015-04-01	17.9
2015-07-01	20.3
2015-10-01	19.2
2016-01-01	18.6
2016-04-01	19.1
2016-07-01	20.8
2016-10-01	19.3
2017-01-01	19.3
2017-04-01	20.5
2017-07-01	23.8
2017-10-01	21.2
2018-01-01	20.8
2018-04-01	22.8
2018-07-01	24.7