Quarter	Percent
1999-01-01	21.2
1999-04-01	21.2
1999-07-01	21.2
1999-10-01	21.1
2000-01-01	21.6
2000-04-01	22.5
2000-07-01	23
2000-10-01	23.6
2001-01-01	23.4
2001-04-01	23.3
2001-07-01	23.8
2001-10-01	24.2
2002-01-01	24.5
2002-04-01	25.1
2002-07-01	24.7
2002-10-01	25.1
2003-01-01	25.3
2003-04-01	26.1
2003-07-01	26.5
2003-10-01	26.8
2004-01-01	27.3
2004-04-01	27.6
2004-07-01	27.5
2004-10-01	27.8
2005-01-01	29.5
2005-04-01	30
2005-07-01	29.5
2005-10-01	30.6
2006-01-01	31.5
2006-04-01	31
2006-07-01	30.3
2006-10-01	31.8
2007-01-01	32.7
2007-04-01	32.9
2007-07-01	32.2
2007-10-01	33.2
2008-01-01	33.7
2008-04-01	34
2008-07-01	33.9
2008-10-01	35.4
2009-01-01	36.2
2009-04-01	37.5
2009-07-01	37
2009-10-01	37.5
2010-01-01	38.1
2010-04-01	37.7
2010-07-01	38.5
2010-10-01	39.5
2011-01-01	40.2
2011-04-01	41.8
2011-07-01	42.6
2011-10-01	42.5
2012-01-01	42.8
2012-04-01	44.2
2012-07-01	44.5
2012-10-01	44
2013-01-01	44.6
2013-04-01	45
2013-07-01	45.2
2013-10-01	46
2014-01-01	46.4
2014-04-01	46.9
2014-07-01	46.5
2014-10-01	47.8
2015-01-01	48.3
2015-04-01	49.0
2015-07-01	49.2
2015-10-01	51.1
2016-01-01	51.5
2016-04-01	51.4
2016-07-01	52.0
2016-10-01	51.9
2017-01-01	51.6
2017-04-01	52.0
2017-07-01	51.5
2017-10-01	52.1
2018-01-01	52.7
2018-04-01	52.8
2018-07-01	52.5