Quarter	Percent, Seasonally Adjusted
2004-01-01	20.2
2004-04-01	20.8
2004-07-01	20.5
2004-10-01	21.5
2005-01-01	21.5
2005-04-01	21.4
2005-07-01	21.8
2005-10-01	21.1
2006-01-01	20.1
2006-04-01	19.0
2006-07-01	18.9
2006-10-01	18.9
2007-01-01	18.2
2007-04-01	17.8
2007-07-01	18.0
2007-10-01	18.9
2008-01-01	18.4
2008-04-01	18.6
2008-07-01	19.1
2008-10-01	20.3
2009-01-01	21.6
2009-04-01	22.2
2009-07-01	24.1
2009-10-01	25.0
2010-01-01	26.1
2010-04-01	27.9
2010-07-01	26.3
2010-10-01	26.3
2011-01-01	25.4
2011-04-01	25.6
2011-07-01	28.2
2011-10-01	29.5
2012-01-01	31.3
2012-04-01	33.7
2012-07-01	34.3
2012-10-01	36.5
2013-01-01	38.6
2013-04-01	38.3
2013-07-01	39.8
2013-10-01	39.9
2014-01-01	41.9
2014-04-01	41.7
2014-07-01	41.0
2014-10-01	39.9
2015-01-01	39.8
2015-04-01	39.9
2015-07-01	37.5
2015-10-01	37.7
2016-01-01	38.4
2016-04-01	36.4
2016-07-01	35.4
2016-10-01	36.3
2017-01-01	34.6
2017-04-01	34.0
2017-07-01	32.7
2017-10-01	31.2
2018-01-01	30.3
2018-04-01	30.1