Quarter	Percent
1998-01-01	15.0
1998-04-01	10.7
1998-07-01	13.4
1998-10-01	13.7
1999-01-01	12.2
1999-04-01	11
1999-07-01	11.2
1999-10-01	10.7
2000-01-01	12.9
2000-04-01	11.8
2000-07-01	11.2
2000-10-01	11.3
2001-01-01	13.4
2001-04-01	12
2001-07-01	10.7
2001-10-01	12.4
2002-01-01	12.4
2002-04-01	12.1
2002-07-01	13.8
2002-10-01	17.5
2003-01-01	17.5
2003-04-01	16.7
2003-07-01	16.6
2003-10-01	17.2
2004-01-01	17.4
2004-04-01	15.9
2004-07-01	18.8
2004-10-01	18.8
2005-01-01	20
2005-04-01	17.6
2005-07-01	20.4
2005-10-01	18.5
2006-01-01	18
2006-04-01	15.6
2006-07-01	19.2
2006-10-01	21.1
2007-01-01	20.7
2007-04-01	19.2
2007-07-01	19.9
2007-10-01	21.4
2008-01-01	20.6
2008-04-01	17.5
2008-07-01	21.2
2008-10-01	21.8
2009-01-01	21.8
2009-04-01	18.6
2009-07-01	22.5
2009-10-01	23.9
2010-01-01	23.7
2010-04-01	20
2010-07-01	25.8
2010-10-01	26.7
2011-01-01	29.6
2011-04-01	27.2
2011-07-01	32.8
2011-10-01	37
2012-01-01	36.8
2012-04-01	36.4
2012-07-01	40.8
2012-10-01	43
2013-01-01	45.2
2013-04-01	40
2013-07-01	35.4
2013-10-01	38.1
2014-01-01	37.9
2014-04-01	34.6
2014-07-01	34.5
2014-10-01	34.6
2015-01-01	38.9
2015-04-01	31.7
2015-07-01	33.6
2015-10-01	33.6
2016-01-01	32.1
2016-04-01	28.2
2016-07-01	27.1
2016-10-01	27.6
2017-01-01	26.3
2017-04-01	22.6
2017-07-01	27.2
2017-10-01	25.8
2018-01-01	19.8
2018-04-01	21.8