Quarter	Percent
1968-01-01	50.0837771527395
1968-04-01	55.8120670932012
1968-07-01	55.0063068600774
1968-10-01	53.0509746937072
1969-01-01	50.0360387560075
1969-04-01	54.9960085905727
1969-07-01	54.4289114193379
1969-10-01	52.5626665616782
1970-01-01	50.0999372274312
1970-04-01	54.8985721730491
1970-07-01	54.3111811680138
1970-10-01	52.1884705251587
1971-01-01	49.9170972187142
1971-04-01	53.5281416501174
1971-07-01	52.9326426155431
1971-10-01	51.2803832146702
1972-01-01	48.7362638067542
1972-04-01	51.7710501604488
1972-07-01	51.8337618689577
1972-10-01	51.5076937157612
1973-01-01	50.0396595059618
1973-04-01	52.2347861858165
1973-07-01	52.1427743008246
1973-10-01	51.6813899768222
1974-01-01	48.2861004994637
1974-04-01	51.4595971459055
1974-07-01	50.4684449284755
1974-10-01	49.2784413493839
1975-01-01	46.5648100571048
1975-04-01	50.3602268899166
1975-07-01	50.3435671519780
1975-10-01	48.6776005096894
1976-01-01	46.9153762357436
1976-04-01	49.9650336177229
1976-07-01	50.5180598097953
1976-10-01	49.3020494471695
1977-01-01	47.4829715431923
1977-04-01	51.5549193487615
1977-07-01	51.3810405371546
1977-10-01	50.4023899366257
1978-01-01	48.3799110376778
1978-04-01	52.3569334481810
1978-07-01	51.9279792479023
1978-10-01	51.2279189074581
1979-01-01	49.2867756101996
1979-04-01	52.5511093667900
1979-07-01	52.3955219883506
1979-10-01	51.5209908062963
1980-01-01	49.2703315513830
1980-04-01	52.7541226010632
1980-07-01	52.9092832619622
1980-10-01	51.5451389949266
1981-01-01	49.2469879518072
1981-04-01	52.8225348887025
1981-07-01	52.6149641088518
1981-10-01	52.3210383947704
1982-01-01	50.3624614851788
1982-04-01	53.1190245483732
1982-07-01	52.6260494251808
1982-10-01	52.6009106036352
1983-01-01	51.3413120686842
1983-04-01	54.2426491202541
1983-07-01	54.0762708101998
1983-10-01	53.1250728068733
1984-01-01	50.8231833939374
1984-04-01	54.1596239725029
1984-07-01	54.2038152514068
1984-10-01	53.4813655044044
1985-01-01	51.6375880612551
1985-04-01	54.2943960173444
1985-07-01	54.1145360644550
1985-10-01	53.0970347062393
1986-01-01	51.7934297629836
1986-04-01	54.3007802257390
1986-07-01	54.1329908115635
1986-10-01	53.2065147442530
1987-01-01	51.4829989478888
1987-04-01	54.5454724734032
1987-07-01	54.2682571726473
1987-10-01	53.7983986317691
1988-01-01	52.3243167074005
1988-04-01	55.2114955707272
1988-07-01	54.7554797092326
1988-10-01	54.0168013034328
1989-01-01	53.0996089564273
1989-04-01	56.2582478912524
1989-07-01	55.7293122442495
1989-10-01	55.2956174924305
1990-01-01	54.4578805045013
1990-04-01	56.9685225891984
1990-07-01	56.5561295136717
1990-10-01	56.1675007347043
1991-01-01	55.2337947984743
1991-04-01	57.6709462438936
1991-07-01	57.3446809915274
1991-10-01	57.1206417309861
1992-01-01	55.6415593670829
1992-04-01	57.9539857715801
1992-07-01	57.2565426625218
1992-10-01	57.3939092402189
1993-01-01	55.1130843568575
1993-04-01	57.6316081454335
1993-07-01	57.0385288275342
1993-10-01	56.9020299868866
1994-01-01	55.2210552906007
1994-04-01	57.8942157470012
1994-07-01	56.7681904699434
1994-10-01	56.4723807766139
1995-01-01	55.4300121794211
1995-04-01	57.4493719810339
1995-07-01	56.8656540410523
1995-10-01	56.3051687537929
1996-01-01	55.4376113115707
1996-04-01	57.6635040468031
1996-07-01	57.5417257379359
1996-10-01	56.7944882168222
1997-01-01	56.2318934373083
1997-04-01	58.1020360845839
1997-07-01	58.2119505176860
1997-10-01	57.5662138968535
1998-01-01	56.6568768346118
1998-04-01	57.9283400847845
1998-07-01	57.6947186128049
1998-10-01	56.8737007528261
1999-01-01	55.6628639579850
1999-04-01	57.5005386991341
1999-07-01	57.2278146395673
1999-10-01	56.7388447085889
2000-01-01	55.5143696526356
2000-04-01	57.4103499220656
2000-07-01	57.1948901478905
2000-10-01	57.1992049698253
2001-01-01	56.5528699140689
2001-04-01	57.5054635311086
2001-07-01	57.0086106560688
2001-10-01	57.1780694941873
2002-01-01	55.7340567713376
2002-04-01	56.6600311732588
2002-07-01	56.8984219931006
2002-10-01	57.0832626690557
2003-01-01	55.7230095615135
2003-04-01	57.2465060250326
2003-07-01	57.2862956115105
2003-10-01	57.2874122550872
2004-01-01	56.4621557258923
2004-04-01	57.6596982057431
2004-07-01	58.1166238431334
2004-10-01	57.5703761266426
2005-01-01	57.0029560513446
2005-04-01	58.7763427338601
2005-07-01	58.7717966864921
2005-10-01	58.0651830435352
2006-01-01	57.7431621531800
2006-04-01	59.3080498046786
2006-07-01	59.3068895692495
2006-10-01	59.1886615900878
2007-01-01	58.2336172743158
2007-04-01	60.3381704981008
2007-07-01	59.7190681391561
2007-10-01	60.0017030772845
2008-01-01	58.9417363735973
2008-04-01	60.4852787979848
2008-07-01	59.9333008358019
2008-10-01	60.1564632654799
2009-01-01	59.2081463278132
2009-04-01	60.0508292039364
2009-07-01	60.1724375652433
2009-10-01	60.0508913582205
2010-01-01	59.4432279333228
2010-04-01	60.2093698188584
2010-07-01	60.6157687210004
2010-10-01	60.5726297641552
2011-01-01	60.2389460960302
2011-04-01	61.3841570569175
2011-07-01	60.9890226212717
2011-10-01	60.7813663471758
2012-01-01	59.7512428592321
2012-04-01	60.9696043821388
2012-07-01	60.9662693503811
2012-10-01	61.2209731309791
2013-01-01	61.5440594701240
2013-04-01	62.4819642049190
2013-07-01	62.6646625461346
2013-10-01	63.4428567142096
2014-01-01	62.7066945412398
2014-04-01	63.6943893520976
2014-07-01	63.9382275222243
2014-10-01	64.6025828233500
2015-01-01	63.7572411366070
2015-04-01	64.6270320392020
2015-07-01	65.0345626475241
2015-10-01	65.3781271767668
2016-01-01	65.2701008190516
2016-04-01	65.7014883630405
2016-07-01	66.7079962886692
2016-10-01	66.7934084613142
2017-01-01	66.3420188825463
2017-04-01	67.3792152084952
2017-07-01	68.0160200883759
2017-10-01	68.1964158359110
2018-01-01	68.7641463025306
2018-04-01	69.5543646378698
2018-07-01	70.1092342414285