Quarter	Ratio
2005-01-01	70.58
2005-04-01	68.41
2005-07-01	66.84
2005-10-01	66.72
2006-01-01	67.85
2006-04-01	66.67
2006-07-01	64.56
2006-10-01	63.48
2007-01-01	63.68
2007-04-01	63.01
2007-07-01	60.64
2007-10-01	60.22
2008-01-01	60.88
2008-04-01	59.77
2008-07-01	58.91
2008-10-01	60.29
2009-01-01	63.75
2009-04-01	63.52
2009-07-01	61.04
2009-10-01	60.44
2010-01-01	61.47
2010-04-01	60.30
2010-07-01	58.10
2010-10-01	57.67
2011-01-01	57.79
2011-04-01	57.69
2011-07-01	56.17
2011-10-01	56.62
2012-01-01	56.83
2012-04-01	57.43
2012-07-01	55.76
2012-10-01	56.34
2013-01-01	57.13
2013-04-01	56.27
2013-07-01	54.63
2013-10-01	54.92
2014-01-01	55.04
2014-04-01	55.07
2014-07-01	53.53
2014-10-01	53.66
2015-01-01	54.10
2015-04-01	53.92
2015-07-01	52.62
2015-10-01	52.60
2016-01-01	53.72
2016-04-01	52.93
2016-07-01	52.58
2016-10-01	52.81
2017-01-01	53.08
2017-04-01	53.20
2017-07-01	52.06
2017-10-01	52.50