Quarter	Percent
1999-01-01	30
1999-04-01	30.8
1999-07-01	34.1
1999-10-01	33.6
2000-01-01	33.3
2000-04-01	33.3
2000-07-01	34.5
2000-10-01	34
2001-01-01	34.8
2001-04-01	34.5
2001-07-01	37.4
2001-10-01	36.1
2002-01-01	35.1
2002-04-01	36.3
2002-07-01	35.6
2002-10-01	35
2003-01-01	31.8
2003-04-01	30.7
2003-07-01	33.8
2003-10-01	30.5
2004-01-01	30.8
2004-04-01	30.4
2004-07-01	32.1
2004-10-01	30.9
2005-01-01	30
2005-04-01	26.4
2005-07-01	30.3
2005-10-01	28.4
2006-01-01	28.8
2006-04-01	26.4
2006-07-01	28.8
2006-10-01	23.8
2007-01-01	19.2
2007-04-01	17.1
2007-07-01	22.8
2007-10-01	21.7
2008-01-01	19.3
2008-04-01	17.8
2008-07-01	21.8
2008-10-01	20.5
2009-01-01	22.8
2009-04-01	22.8
2009-07-01	29.7
2009-10-01	30.1
2010-01-01	31
2010-04-01	30.3
2010-07-01	33
2010-10-01	33.4
2011-01-01	32.6
2011-04-01	31.5
2011-07-01	35.3
2011-10-01	35.8
2012-01-01	31.5
2012-04-01	29.7
2012-07-01	34.5
2012-10-01	34.1
2013-01-01	28.1
2013-04-01	30
2013-07-01	34.6
2013-10-01	33.8
2014-01-01	32.6
2014-04-01	31.8
2014-07-01	30.5
2014-10-01	25.6
2015-01-01	26.1
2015-04-01	26.0
2015-07-01	29.1
2015-10-01	28.8
2016-01-01	27.4
2016-04-01	25.7
2016-07-01	27.1
2016-10-01	25.2
2017-01-01	20.7
2017-04-01	17.4
2017-07-01	20.6
2017-10-01	22.0
2018-01-01	16.5
2018-04-01	15.6