Quarter	Percent
1998-01-01	30
1998-04-01	30.2
1998-07-01	28.3
1998-10-01	30.8
1999-01-01	31
1999-04-01	28.6
1999-07-01	27.8
1999-10-01	29.6
2000-01-01	29
2000-04-01	28.4
2000-07-01	26.4
2000-10-01	26.8
2001-01-01	26.1
2001-04-01	24.8
2001-07-01	23.8
2001-10-01	25.4
2002-01-01	25.4
2002-04-01	23.7
2002-07-01	23
2002-10-01	24
2003-01-01	25.8
2003-04-01	23.7
2003-07-01	22.7
2003-10-01	24.7
2004-01-01	20.3
2004-04-01	21
2004-07-01	19
2004-10-01	22.2
2005-01-01	23
2005-04-01	20.9
2005-07-01	20.3
2005-10-01	22.2
2006-01-01	21.2
2006-04-01	18.1
2006-07-01	17.4
2006-10-01	20.3
2007-01-01	18.9
2007-04-01	17
2007-07-01	16.7
2007-10-01	20.9
2008-01-01	18.5
2008-04-01	17.4
2008-07-01	18
2008-10-01	21.6
2009-01-01	23.2
2009-04-01	21.3
2009-07-01	21.9
2009-10-01	26.3
2010-01-01	28.3
2010-04-01	27.5
2010-07-01	23.8
2010-10-01	27.7
2011-01-01	27.7
2011-04-01	24.2
2011-07-01	25.2
2011-10-01	31
2012-01-01	33.3
2012-04-01	33.4
2012-07-01	31
2012-10-01	37.3
2013-01-01	41.3
2013-04-01	37.5
2013-07-01	37
2013-10-01	40.2
2014-01-01	44.6
2014-04-01	41.7
2014-07-01	38.5
2014-10-01	40.4
2015-01-01	42.1
2015-04-01	39.8
2015-07-01	34.1
2015-10-01	39.3
2016-01-01	39.8
2016-04-01	35.1
2016-07-01	32.3
2016-10-01	38.7
2017-01-01	35.8
2017-04-01	33.2
2017-07-01	30.4
2017-10-01	32.7
2018-01-01	31.4
2018-04-01	29.9