Quarter	Percent
1999-01-01	10.3
1999-04-01	11.1
1999-07-01	11.8
1999-10-01	11.9
2000-01-01	11.9
2000-04-01	13
2000-07-01	13.7
2000-10-01	14.6
2001-01-01	14.1
2001-04-01	14.2
2001-07-01	15.4
2001-10-01	15.7
2002-01-01	16.2
2002-04-01	17
2002-07-01	17.8
2002-10-01	19.5
2003-01-01	20.2
2003-04-01	21.2
2003-07-01	22.3
2003-10-01	23.4
2004-01-01	24
2004-04-01	24.5
2004-07-01	25.3
2004-10-01	26.4
2005-01-01	26.1
2005-04-01	26.7
2005-07-01	27.1
2005-10-01	27.1
2006-01-01	26.7
2006-04-01	26.9
2006-07-01	26.4
2006-10-01	26.5
2007-01-01	25.9
2007-04-01	26.7
2007-07-01	25.5
2007-10-01	25.1
2008-01-01	24.8
2008-04-01	24.7
2008-07-01	25.7
2008-10-01	25.8
2009-01-01	25.5
2009-04-01	26
2009-07-01	26
2009-10-01	27.7
2010-01-01	27.9
2010-04-01	28.7
2010-07-01	30
2010-10-01	31
2011-01-01	31.5
2011-04-01	31.8
2011-07-01	32.3
2011-10-01	31.9
2012-01-01	31.2
2012-04-01	32.1
2012-07-01	32.3
2012-10-01	31.3
2013-01-01	31.1
2013-04-01	31.8
2013-07-01	32.3
2013-10-01	33.4
2014-01-01	33.9
2014-04-01	35
2014-07-01	35.7
2014-10-01	36.1
2015-01-01	36.1
2015-04-01	37.6
2015-07-01	38.5
2015-10-01	38.6
2016-01-01	39.5
2016-04-01	41.8
2016-07-01	42.3
2016-10-01	42.5
2017-01-01	41.2
2017-04-01	42.0
2017-07-01	42.9
2017-10-01	43.6
2018-01-01	44.8
2018-04-01	44.6