Quarter	Percent
2005-01-01	19.3
2005-04-01	16.9
2005-07-01	12.7
2005-10-01	14.1
2006-01-01	11.3
2006-04-01	9.8
2006-07-01	10.1
2006-10-01	8.7
2007-01-01	10.5
2007-04-01	6.7
2007-07-01	8.6
2007-10-01	7.9
2008-01-01	10.0
2008-04-01	11.0
2008-07-01	14.8
2008-10-01	17.2
2009-01-01	25.5
2009-04-01	30.4
2009-07-01	32.8
2009-10-01	29.5
2010-01-01	36.5
2010-04-01	37.4
2010-07-01	35.8
2010-10-01	33.5
2011-01-01	33.9
2011-04-01	33.8
2011-07-01	31.7
2011-10-01	30.8
2012-01-01	28.7
2012-04-01	25.2
2012-07-01	27.4
2012-10-01	25.5
2013-01-01	22.7
2013-04-01	21.0
2013-07-01	23.1
2013-10-01	20.7
2014-01-01	21.2
2014-04-01	21.3
2014-07-01	16.4
2014-10-01	18.3
2015-01-01	19.9
2015-04-01	16.7
2015-07-01	15.3
2015-10-01	13.3
2016-01-01	14.5
2016-04-01	15.7
2016-07-01	13.1
2016-10-01	14.6
2017-01-01	14.8
2017-04-01	13.1
2017-07-01	12.0
2017-10-01	13.1
2018-01-01	13.9
2018-04-01	10.9