Quarter	Percent
1999-01-01	30.9
1999-04-01	32.9
1999-07-01	37.5
1999-10-01	34.7
2000-01-01	30.1
2000-04-01	31.2
2000-07-01	36.9
2000-10-01	32.8
2001-01-01	29.9
2001-04-01	30.3
2001-07-01	33.5
2001-10-01	28.5
2002-01-01	30.5
2002-04-01	31.1
2002-07-01	31.9
2002-10-01	28.6
2003-01-01	27.6
2003-04-01	28.6
2003-07-01	29.3
2003-10-01	30.9
2004-01-01	31.4
2004-04-01	33.8
2004-07-01	37.4
2004-10-01	32.8
2005-01-01	33.2
2005-04-01	31.7
2005-07-01	37.3
2005-10-01	33.9
2006-01-01	32.1
2006-04-01	35.3
2006-07-01	39.1
2006-10-01	33.4
2007-01-01	34.6
2007-04-01	37.2
2007-07-01	43
2007-10-01	35.7
2008-01-01	34.4
2008-04-01	37.3
2008-07-01	44.9
2008-10-01	37
2009-01-01	31.3
2009-04-01	34.7
2009-07-01	41.4
2009-10-01	33.7
2010-01-01	33.5
2010-04-01	32.9
2010-07-01	36.5
2010-10-01	33.4
2011-01-01	28.7
2011-04-01	30.9
2011-07-01	34.7
2011-10-01	31.9
2012-01-01	28
2012-04-01	25.8
2012-07-01	29.2
2012-10-01	26.3
2013-01-01	24.7
2013-04-01	25.8
2013-07-01	30.6
2013-10-01	25.2
2014-01-01	23.1
2014-04-01	26.7
2014-07-01	29.6
2014-10-01	27.8
2015-01-01	26.0
2015-04-01	30.0
2015-07-01	33.7
2015-10-01	28.6
2016-01-01	25.8
2016-04-01	27.9
2016-07-01	31.8
2016-10-01	29.0
2017-01-01	31.7
2017-04-01	34.4
2017-07-01	39.6
2017-10-01	33.3
2018-01-01	33.9
2018-04-01	37.1