Month	Percent
1997-01-01	25.4
1997-02-01	25
1997-03-01	24.2
1997-04-01	23.4
1997-05-01	22.8
1997-06-01	22.8
1997-07-01	23
1997-08-01	22.8
1997-09-01	22.6
1997-10-01	22.2
1997-11-01	21.9
1997-12-01	22
1998-01-01	22.4
1998-02-01	22.6
1998-03-01	22.2
1998-04-01	21.7
1998-05-01	21.3
1998-06-01	21.3
1998-07-01	21.7
1998-08-01	22.1
1998-09-01	22.6
1998-10-01	23.1
1998-11-01	23.7
1998-12-01	24.7
1999-01-01	26.5
1999-02-01	28.3
1999-03-01	29
1999-04-01	29.1
1999-05-01	28.8
1999-06-01	28.7
1999-07-01	29.4
1999-08-01	30.6
1999-09-01	31.7
1999-10-01	32.3
1999-11-01	32.8
1999-12-01	33.8
2000-01-01	36.0
2000-02-01	37.2
2000-03-01	37.3
2000-04-01	36.8
2000-05-01	35.7
2000-06-01	34.5
2000-07-01	33.6
2000-08-01	33.1
2000-09-01	33.1
2000-10-01	33.1
2000-11-01	33.8
2000-12-01	35.3
2001-01-01	37.5
2001-02-01	38.6
2001-03-01	39.2
2001-04-01	39.4
2001-05-01	39.2
2001-06-01	39.1
2001-07-01	39.2
2001-08-01	39.5
2001-09-01	40
2001-10-01	40.2
2001-11-01	40.9
2001-12-01	41.7
2002-01-01	42.7
2002-02-01	42.9
2002-03-01	42.7
2002-04-01	42.3
2002-05-01	41.2
2002-06-01	41.4
2002-07-01	41.8
2002-08-01	42.3
2002-09-01	42.8
2002-10-01	43
2002-11-01	43.5
2002-12-01	43.9
2003-01-01	44.4
2003-02-01	44.1
2003-03-01	43.3
2003-04-01	42.1
2003-05-01	41.1
2003-06-01	41
2003-07-01	41.5
2003-08-01	41.6
2003-09-01	41.3
2003-10-01	40.5
2003-11-01	40.6
2003-12-01	41.4
2004-01-01	43.1
2004-02-01	43.4
2004-03-01	42.8
2004-04-01	41.3
2004-05-01	39.9
2004-06-01	39.1
2004-07-01	38.5
2004-08-01	37.9
2004-09-01	37.4
2004-10-01	36.8
2004-11-01	36.9
2004-12-01	37.9
2005-01-01	38.4
2005-02-01	39.7
2005-03-01	40.2
2005-04-01	39.7
2005-05-01	38.7
2005-06-01	37.4
2005-07-01	35.9
2005-08-01	35
2005-09-01	34.7
2005-10-01	34.4
2005-11-01	34.4
2005-12-01	34.6
2006-01-01	35.1
2006-02-01	34.5
2006-03-01	33.4
2006-04-01	31.5
2006-05-01	29.9
2006-06-01	28.7
2006-07-01	28.1
2006-08-01	27.8
2006-09-01	27.8
2006-10-01	27.4
2006-11-01	27
2006-12-01	26.6
2007-01-01	26.6
2007-02-01	25.8
2007-03-01	24.3
2007-04-01	22.6
2007-05-01	21.5
2007-06-01	20.7
2007-07-01	20.9
2007-08-01	20.6
2007-09-01	20.3
2007-10-01	19
2007-11-01	18.5
2007-12-01	18.4
2008-01-01	19.3
2008-02-01	19.1
2008-03-01	18.2
2008-04-01	17.5
2008-05-01	17.1
2008-06-01	16.3
2008-07-01	15.9
2008-08-01	15.9
2008-09-01	16.3
2008-10-01	16.5
2008-11-01	17
2008-12-01	17.5
2009-01-01	18.8
2009-02-01	19.4
2009-03-01	19.3
2009-04-01	18.8
2009-05-01	19
2009-06-01	19.5
2009-07-01	21
2009-08-01	21.6
2009-09-01	22.5
2009-10-01	22.1
2009-11-01	22.2
2009-12-01	22.6
2010-01-01	24.4
2010-02-01	24.9
2010-03-01	24.5
2010-04-01	23.2
2010-05-01	23.1
2010-06-01	22.9
2010-07-01	23.1
2010-08-01	23.2
2010-09-01	24.1
2010-10-01	23.3
2010-11-01	23.2
2010-12-01	24.1
2011-01-01	26.2
2011-02-01	27
2011-03-01	26.7
2011-04-01	25.2
2011-05-01	24.5
2011-06-01	24
2011-07-01	24.7
2011-08-01	25.2
2011-09-01	26.3
2011-10-01	26.2
2011-11-01	26.4
2011-12-01	26.7
2012-01-01	27.9
2012-02-01	28
2012-03-01	27.1
2012-04-01	25.7
2012-05-01	25.1
2012-06-01	24.6
2012-07-01	25
2012-08-01	25.6
2012-09-01	26.7
2012-10-01	26.8
2012-11-01	27.4
2012-12-01	27.9
2013-01-01	29.6
2013-02-01	29.6
2013-03-01	28.4
2013-04-01	26.8
2013-05-01	25.8
2013-06-01	25.4
2013-07-01	26
2013-08-01	26.4
2013-09-01	27.6
2013-10-01	27.3
2013-11-01	27.4
2013-12-01	27.3
2014-01-01	28.2
2014-02-01	27.6
2014-03-01	25.9
2014-04-01	24
2014-05-01	22.9
2014-06-01	22.3
2014-07-01	22.9
2014-08-01	22.9
2014-09-01	23.4
2014-10-01	22.1
2014-11-01	21.9
2014-12-01	21.9
2015-01-01	23.6
2015-02-01	23.7
2015-03-01	22.5
2015-04-01	20.9
2015-05-01	19.7
2015-06-01	18.8
2015-07-01	19.1
2015-08-01	19.5
2015-09-01	20.7
2015-10-01	20.5
2015-11-01	20.2
2015-12-01	20.0
2016-01-01	20.3
2016-02-01	19.9
2016-03-01	18.6
2016-04-01	17.2
2016-05-01	16.9
2016-06-01	16.7
2016-07-01	17.5
2016-08-01	18.0
2016-09-01	18.6
2016-10-01	17.0
2016-11-01	15.8
2016-12-01	15.1
2017-01-01	15.4
2017-02-01	15.3
2017-03-01	15.0
2017-04-01	14.7
2017-05-01	14.9
2017-06-01	14.3
2017-07-01	14.1
2017-08-01	14.4
2017-09-01	15.6
2017-10-01	15.7
2017-11-01	14.9
2017-12-01	13.6
2018-01-01	12.8
2018-02-01	11.7
2018-03-01	10.8
2018-04-01	10.4
2018-05-01	10.3
2018-06-01	9.8
2018-07-01	9.8
2018-08-01	10.0
2018-09-01	11.0