Quarter	Percent
1968-01-01	61.4475036534473
1968-04-01	66.5802220797186
1968-07-01	66.8087522058939
1968-10-01	64.9697916394480
1969-01-01	62.0022646141220
1969-04-01	66.7352159191094
1969-07-01	66.2222228700219
1969-10-01	64.4610041664740
1970-01-01	61.7844900066933
1970-04-01	65.9295329252024
1970-07-01	65.8532273647733
1970-10-01	63.2793238094115
1971-01-01	61.5424932081620
1971-04-01	66.2268431823604
1971-07-01	65.9251208176128
1971-10-01	64.4769134101430
1972-01-01	60.5535584936460
1972-04-01	64.9008468589012
1972-07-01	64.7337618948872
1972-10-01	62.8756080231732
1973-01-01	61.6986877751916
1973-04-01	64.1661971427194
1973-07-01	64.8420662955827
1973-10-01	64.5857418111753
1974-01-01	61.2986054636908
1974-04-01	64.1184620590804
1974-07-01	64.2612132641231
1974-10-01	62.7412300283458
1975-01-01	60.3321100539291
1975-04-01	63.9746937664203
1975-07-01	64.5164108454496
1975-10-01	62.4450458062212
1976-01-01	60.4990522745411
1976-04-01	63.9625629167443
1976-07-01	64.7600427287606
1976-10-01	62.4418290593161
1977-01-01	59.5453707488718
1977-04-01	63.5261467314439
1977-07-01	63.8800418042433
1977-10-01	62.7301577316256
1978-01-01	60.1413849557732
1978-04-01	64.3682263009802
1978-07-01	64.2271600994994
1978-10-01	63.1169266687293
1979-01-01	60.4930712739599
1979-04-01	64.6210595769724
1979-07-01	64.5420992547454
1979-10-01	63.0663072769294
1980-01-01	60.8539516782215
1980-04-01	65.0715809180654
1980-07-01	64.8859545922905
1980-10-01	62.3915495994959
1981-01-01	60.6402162969524
1981-04-01	64.3127230656934
1981-07-01	64.2240353005135
1981-10-01	62.4871298912122
1982-01-01	60.9836843086789
1982-04-01	64.7337551842866
1982-07-01	64.3132883436706
1982-10-01	62.7893342258524
1983-01-01	61.8932712049044
1983-04-01	65.0973424687318
1983-07-01	65.0658848289561
1983-10-01	63.5477939372003
1984-01-01	61.3476917587264
1984-04-01	64.3354996497218
1984-07-01	64.0142586868564
1984-10-01	62.7246858699661
1985-01-01	61.2657033031549
1985-04-01	64.9140494854781
1985-07-01	64.0786866479967
1985-10-01	62.4993999133953
1986-01-01	60.8193904700476
1986-04-01	63.6881396640678
1986-07-01	64.1725551143554
1986-10-01	63.1427320898427
1987-01-01	61.1851610819716
1987-04-01	64.0754884016075
1987-07-01	64.1722258590327
1987-10-01	63.3966819049178
1988-01-01	61.7797227123637
1988-04-01	63.8822097909980
1988-07-01	64.2207354429681
1988-10-01	63.0103737454608
1989-01-01	62.1143164530968
1989-04-01	64.5709821914702
1989-07-01	64.7657001050183
1989-10-01	64.3262742700006
1990-01-01	62.9670105524487
1990-04-01	65.6800150227689
1990-07-01	65.8255186268036
1990-10-01	65.2478666811625
1991-01-01	64.4206237019520
1991-04-01	66.8634414130226
1991-07-01	67.3164427648709
1991-10-01	66.2440535926877
1992-01-01	65.3341872314489
1992-04-01	66.4495546342386
1992-07-01	66.9925088361899
1992-10-01	66.6816822004660
1993-01-01	65.6610791748857
1993-04-01	67.1058312033194
1993-07-01	67.4065661001757
1993-10-01	65.9770415614877
1994-01-01	64.9518345136110
1994-04-01	66.8428781182574
1994-07-01	67.0336606216503
1994-10-01	65.7230634189160
1995-01-01	64.9607775931338
1995-04-01	67.0669854951831
1995-07-01	66.7823785715635
1995-10-01	66.2047514605471
1996-01-01	64.4676700008527
1996-04-01	66.8165515100279
1996-07-01	67.4150528507484
1996-10-01	67.0356265144954
1997-01-01	65.5973383025108
1997-04-01	67.4890129647441
1997-07-01	67.4729305808474
1997-10-01	66.9717282592019
1998-01-01	66.0792775838401
1998-04-01	67.7507179639289
1998-07-01	67.7021268458386
1998-10-01	66.8308193210846
1999-01-01	66.5714426874085
1999-04-01	67.6337704982889
1999-07-01	67.6829763364332
1999-10-01	66.7941570698348
2000-01-01	65.8571010515340
2000-04-01	66.6869095133697
2000-07-01	67.0731212485588
2000-10-01	66.3520588713091
2001-01-01	65.8149012692782
2001-04-01	65.9472502901508
2001-07-01	65.9427644314668
2001-10-01	65.5111475559200
2002-01-01	65.3524301549072
2002-04-01	65.6550878508987
2002-07-01	65.6222857102098
2002-10-01	65.4922060542588
2003-01-01	65.4040490468583
2003-04-01	65.8640132207801
2003-07-01	66.1109099706836
2003-10-01	66.2190952027739
2004-01-01	65.3179777287088
2004-04-01	66.1738586352326
2004-07-01	66.6300793892651
2004-10-01	66.2443464162352
2005-01-01	65.9096886602593
2005-04-01	66.7264163538313
2005-07-01	67.3389758217626
2005-10-01	66.4417338632774
2006-01-01	66.4773745957742
2006-04-01	67.6936546208376
2006-07-01	67.6164148324544
2006-10-01	67.6121423265880
2007-01-01	67.8521171043457
2007-04-01	68.4495068392973
2007-07-01	68.8763735346181
2007-10-01	68.8302550571680
2008-01-01	68.3051665220898
2008-04-01	69.4464636629276
2008-07-01	69.2147086382975
2008-10-01	68.9048958104645
2009-01-01	68.6598788469206
2009-04-01	69.1140495179832
2009-07-01	69.2582663092046
2009-10-01	68.7276574264842
2010-01-01	68.7310253942876
2010-04-01	68.9317247846893
2010-07-01	69.2044942753752
2010-10-01	68.7902373827493
2011-01-01	68.8630463225673
2011-04-01	69.6639204992195
2011-07-01	68.5848594195636
2011-10-01	68.7346890669031
2012-01-01	68.3781612621339
2012-04-01	68.1252593429948
2012-07-01	68.0201920179404
2012-10-01	68.6696416020463
2013-01-01	69.3211044611164
2013-04-01	69.0090946577892
2013-07-01	69.6768014501364
2013-10-01	70.1973229120645
2014-01-01	70.4214237692302
2014-04-01	70.9911804421266
2014-07-01	71.2811997142712
2014-10-01	71.4710394802648
2015-01-01	72.0360541672032
2015-04-01	71.8211491054963
2015-07-01	72.9958517525213
2015-10-01	72.7745633371209
2016-01-01	73.1193908795783
2016-04-01	73.2614650674603
2016-07-01	74.3208985322548
2016-10-01	74.0817908467098
2017-01-01	74.6509697952334
2017-04-01	74.9519029367116
2017-07-01	76.0609647606395
2017-10-01	76.0094898173287
2018-01-01	76.4335430519791
2018-04-01	76.9062300811436
2018-07-01	77.2917481670668