Quarter	Percent
1999-01-01	35
2000-01-01	31.3
2000-04-01	32.1
2000-07-01	32.2
2000-10-01	29.8
2001-01-01	28.5
2001-04-01	31.6
2001-07-01	31.3
2001-10-01	29.3
2002-01-01	28.9
2002-04-01	29.7
2002-07-01	28.9
2002-10-01	29
2003-01-01	29.4
2003-04-01	30.3
2003-07-01	30.5
2003-10-01	30.4
2004-01-01	28.8
2004-04-01	29.3
2004-07-01	30.2
2004-10-01	30
2005-01-01	28.7
2005-04-01	29.8
2005-07-01	32.2
2005-10-01	31.3
2006-01-01	29
2006-04-01	29.8
2006-07-01	32.1
2006-10-01	31.6
2007-01-01	30.7
2007-04-01	31.2
2007-07-01	32.4
2007-10-01	32.9
2008-01-01	32.7
2008-04-01	33.3
2008-07-01	33.6
2008-10-01	33.8
2009-01-01	33.7
2009-04-01	33.9
2009-07-01	35.2
2009-10-01	35.1
2010-01-01	35.3
2010-04-01	36
2010-07-01	37.4
2010-10-01	38
2011-01-01	38.3
2011-04-01	39.4
2011-07-01	40.3
2011-10-01	40.5
2012-01-01	40
2012-04-01	41.6
2012-07-01	42.7
2012-10-01	42.8
2013-01-01	42.7
2013-04-01	43.6
2013-07-01	44.5
2013-10-01	45.1
2014-01-01	44.6
2014-04-01	44.8
2014-07-01	46.1
2014-10-01	46.7
2015-01-01	45.9
2015-04-01	45.4
2015-07-01	47.8
2015-10-01	48.4
2016-01-01	47.3
2016-04-01	47.3
2016-07-01	48.7
2016-10-01	49.9
2017-01-01	49.1
2017-04-01	50.2
2017-07-01	51.1
2017-10-01	50.1
2018-01-01	49.3
2018-04-01	50.6