Quarter	Percent
1999-01-01	32.5
2000-01-01	28.4
2000-04-01	29
2000-07-01	29.5
2000-10-01	26.7
2001-01-01	25.6
2001-04-01	28.6
2001-07-01	28.4
2001-10-01	26.8
2002-01-01	26.1
2002-04-01	26.6
2002-07-01	25.8
2002-10-01	26.1
2003-01-01	26.6
2003-04-01	27.1
2003-07-01	27
2003-10-01	26.9
2004-01-01	25.5
2004-04-01	26.1
2004-07-01	26.7
2004-10-01	26.5
2005-01-01	25.4
2005-04-01	26.8
2005-07-01	28.7
2005-10-01	27.9
2006-01-01	26.6
2006-04-01	27.3
2006-07-01	29.5
2006-10-01	28.8
2007-01-01	28.5
2007-04-01	29.2
2007-07-01	30.3
2007-10-01	30.6
2008-01-01	30.5
2008-04-01	31.8
2008-07-01	32
2008-10-01	32
2009-01-01	31.4
2009-04-01	31.7
2009-07-01	33.2
2009-10-01	33
2010-01-01	32.6
2010-04-01	33.3
2010-07-01	34.9
2010-10-01	35.4
2011-01-01	35.5
2011-04-01	36.6
2011-07-01	37.7
2011-10-01	37.7
2012-01-01	36.9
2012-04-01	38.3
2012-07-01	39.6
2012-10-01	39.8
2013-01-01	39
2013-04-01	39.9
2013-07-01	41.3
2013-10-01	42
2014-01-01	41.1
2014-04-01	41.7
2014-07-01	43.3
2014-10-01	43.7
2015-01-01	42.9
2015-04-01	43.0
2015-07-01	45.3
2015-10-01	46.1
2016-01-01	45.0
2016-04-01	45.3
2016-07-01	46.6
2016-10-01	47.7
2017-01-01	47.0
2017-04-01	48.2
2017-07-01	49.4
2017-10-01	48.5
2018-01-01	47.6
2018-04-01	49.4