Quarter	Percent
1986-01-01	74.0089366291739
1986-04-01	73.4857223512005
1986-07-01	73.1904024018207
1986-10-01	73.0676398323457
1987-01-01	73.5198042462835
1987-04-01	73.7950126614876
1987-07-01	72.9704276204981
1987-10-01	73.5036038119693
1988-01-01	74.1807859195672
1988-04-01	74.9289260059569
1988-07-01	74.9386440331322
1988-10-01	75.0043353904279
1989-01-01	76.0824206286218
1989-04-01	75.7931839509281
1989-07-01	75.6322174121955
1989-10-01	75.8919225104792
1990-01-01	76.2669870956688
1990-04-01	75.4369160712884
1990-07-01	75.1505425782174
1990-10-01	75.3645240972420
1991-01-01	76.3735170437713
1991-04-01	75.3181395082728
1991-07-01	75.6009154721361
1991-10-01	75.6210002266901
1992-01-01	75.9071848038546
1992-04-01	75.2965079748932
1992-07-01	75.1332927885432
1992-10-01	76.0087268993840
1993-01-01	76.9240431411454
1993-04-01	76.8690083660374
1993-07-01	77.3126029610599
1993-10-01	77.7960923474262
1994-01-01	78.4516563268173
1994-04-01	77.1936359171987
1994-07-01	76.9692273908126
1994-10-01	77.4949514118514
1995-01-01	77.6785530904565
1995-04-01	76.4644409223376
1995-07-01	76.2967200998487
1995-10-01	76.1689431728125
1996-01-01	76.1731140184502
1996-04-01	75.5265277590858
1996-07-01	74.6057839025844
1996-10-01	75.4632902117187
1997-01-01	75.2430139077509
1997-04-01	74.4994847782572
1997-07-01	74.3931060781778
1997-10-01	74.6289633680848
1998-01-01	74.7914551665144
1998-04-01	74.4618050172098
1998-07-01	74.5953728814539
1998-10-01	75.1967621204891
1999-01-01	74.7969446916017
1999-04-01	74.4835890067075
1999-07-01	74.4567673420200
1999-10-01	74.8304023867350
2000-01-01	74.1865829304085
2000-04-01	74.0731537712670
2000-07-01	73.7508522989035
2000-10-01	73.6196319018405
2001-01-01	73.0350618760437
2001-04-01	73.4204461451494
2001-07-01	73.6883152438212
2001-10-01	73.5675153539702
2002-01-01	73.2605117462218
2002-04-01	72.9873970737381
2002-07-01	72.6989764607126
2002-10-01	73.0905822479930
2003-01-01	73.0931874578216
2003-04-01	73.2039943235638
2003-07-01	72.6843451041870
2003-10-01	72.8019000939399
2004-01-01	72.4041052789976
2004-04-01	72.3420644535160
2004-07-01	72.2129295022947
2004-10-01	73.0533057580046
2005-01-01	72.6749281518907
2005-04-01	72.5247166385704
2005-07-01	72.4794976318874
2005-10-01	72.0176620762046
2006-01-01	72.6507623460719
2006-04-01	71.5221396144483
2006-07-01	71.2920162633249
2006-10-01	71.2228287977091
2007-01-01	71.7664802878925
2007-04-01	71.1457539294759
2007-07-01	70.9676848373750
2007-10-01	71.6164756349200
2008-01-01	72.2711045552924
2008-04-01	71.8033404691324
2008-07-01	71.4408081439658
2008-10-01	71.6257088519265
2009-01-01	71.5125121949459
2009-04-01	71.3308433807981
2009-07-01	70.8607089996751
2009-10-01	70.2727178621925
2010-01-01	71.5216854452848
2010-04-01	71.7846635329273
2010-07-01	72.5793138511532
2010-10-01	72.4627665984773
2011-01-01	73.1953796613312
2011-04-01	72.7922030737184
2011-07-01	72.7681533580244
2011-10-01	72.0867106899722
2012-01-01	72.5100555449148
2012-04-01	71.9625248352330
2012-07-01	71.3997122823855
2012-10-01	71.8316159094381
2013-01-01	72.0844631677258
2013-04-01	71.7956082666920
2013-07-01	71.3694262676155
2013-10-01	71.9673357833176
2014-01-01	72.1781961602378
2014-04-01	71.5712745930521
2014-07-01	70.7763822467773
2014-10-01	71.7883007575317
2015-01-01	71.8550986857591
2015-04-01	71.3435925083131
2015-07-01	71.4300020952755
2015-10-01	71.3025603008496
2016-01-01	71.6457583458154
2016-04-01	71.2211866140047
2016-07-01	71.1718130280118
2016-10-01	71.0293412879567
2017-01-01	71.5988553865713
2017-04-01	71.2570963033466
2017-07-01	70.9343754926776
2017-10-01	71.1178583653726
2018-01-01	70.9543665599884
2018-04-01	70.9740041159728
2018-07-01	70.1856074690695