Quarterly Percent
1999-01-01 40.1
1999-04-01 39.5
1999-07-01 39.4
1999-10-01 38.3
2000-01-01 37.5
2000-04-01 37.3
2000-07-01 37.2
2000-10-01 36.6
2001-01-01 38.9
2001-04-01 39.1
2001-07-01 38.9
2001-10-01 38
2002-01-01 36.1
2002-04-01 35.3
2002-07-01 35
2002-10-01 34.4
2003-01-01 33.5
2003-04-01 33.1
2003-07-01 32.8
2003-10-01 31.8
2004-01-01 31.6
2004-04-01 31.2
2004-07-01 31.1
2004-10-01 29.8
2005-01-01 30.5
2005-04-01 30.1
2005-07-01 30.8
2005-10-01 29.4
2006-01-01 28.9
2006-04-01 28.3
2006-07-01 28.6
2006-10-01 27.2
2007-01-01 26.9
2007-04-01 26.9
2007-07-01 27.1
2007-10-01 25.9
2008-01-01 25.4
2008-04-01 25
2008-07-01 25.2
2008-10-01 23.4
2009-01-01 22.9
2009-04-01 22.9
2009-07-01 23.3
2009-10-01 22.2
2010-01-01 21.6
2010-04-01 21.2
2010-07-01 21.6
2010-10-01 20.6
2011-01-01 20.4
2011-04-01 20
2011-07-01 20.8
2011-10-01 19.9
2012-01-01 18.9
2012-04-01 19.2
2012-07-01 19.3
2012-10-01 18.3
2013-01-01 18.1
2013-04-01 18.1
2013-07-01 18.7
2013-10-01 17.9
2014-01-01 17.9
2014-04-01 17.8
2014-07-01 18.7
2014-10-01 17.6
2015-01-01 17.9
2015-04-01 17.4
2015-07-01 18.9
2015-10-01 17.7
2016-01-01 17.7
2016-04-01 17.3
2016-07-01 18.1
2016-10-01 17.6
2017-01-01 17.7
2017-04-01 18.0
2017-07-01 18.5
2017-10-01 17.8
2018-01-01 18.1
2018-04-01 17.8
2018-07-01 18.7