Quarter	Percent
1968-01-01	46.6872363850340
1968-04-01	41.8667310819937
1968-07-01	42.7622378262397
1968-10-01	43.9858085938776
1969-01-01	47.0228073235257
1969-04-01	42.7084552420470
1969-07-01	43.4098381405019
1969-10-01	44.3984755061123
1970-01-01	47.3129264255853
1970-04-01	42.7718178948748
1970-07-01	43.6573883969804
1970-10-01	45.4375219209389
1971-01-01	47.7364403286329
1971-04-01	45.1011258041493
1971-07-01	45.3645762460977
1971-10-01	46.2362627692725
1972-01-01	48.6489236393896
1972-04-01	45.8356440970784
1972-07-01	45.6032830255277
1972-10-01	45.5234324730559
1973-01-01	46.9963494679566
1973-04-01	44.9490945413412
1973-07-01	45.0552275660348
1973-10-01	45.1658225121982
1974-01-01	47.9319318929608
1974-04-01	45.5718829456879
1974-07-01	46.4936121940756
1974-10-01	47.3271544664410
1975-01-01	49.6844297600225
1975-04-01	46.4251175985227
1975-07-01	46.3079539191890
1975-10-01	47.5613189777697
1976-01-01	49.0640427208479
1976-04-01	46.3502431280582
1976-07-01	45.7710591802930
1976-10-01	46.6402665231232
1977-01-01	48.0623845216799
1977-04-01	44.4555797625043
1977-07-01	44.5663424916304
1977-10-01	45.1238390092879
1978-01-01	46.6465850701833
1978-04-01	43.2159347738018
1978-07-01	43.7330805935028
1978-10-01	43.7613515443865
1979-01-01	45.3858673058723
1979-04-01	42.7443215183879
1979-07-01	43.1052182773680
1979-10-01	43.0370491832080
1980-01-01	44.8621839349831
1980-04-01	42.2938750997614
1980-07-01	42.5646403140398
1980-10-01	42.8211780763431
1981-01-01	44.7732239643825
1981-04-01	41.9536458617320
1981-07-01	42.3028215824149
1981-10-01	41.5043682577647
1982-01-01	43.0255107247872
1982-04-01	41.1595486071080
1982-07-01	41.6412380641091
1982-10-01	40.8779625097596
1983-01-01	41.6325397121766
1983-04-01	39.6041621517861
1983-07-01	39.5489863351065
1983-10-01	40.0538887994267
1984-01-01	41.5393403397788
1984-04-01	39.0858003285587
1984-07-01	39.0489551817395
1984-10-01	39.0341476066682
1985-01-01	40.6777394087393
1985-04-01	38.5896599598147
1985-07-01	38.6289387687338
1985-10-01	39.1176684094813
1986-01-01	40.0100155683987
1986-04-01	37.9167974966022
1986-07-01	38.3383423042428
1986-10-01	38.9071457447123
1987-01-01	39.8142513069981
1987-04-01	37.2640770143986
1987-07-01	37.9168345822358
1987-10-01	38.0226079978794
1988-01-01	38.7675295485319
1988-04-01	36.5191062374525
1988-07-01	37.0597377681735
1988-10-01	37.4380303711108
1989-01-01	37.8146136329532
1989-04-01	35.5035234881491
1989-07-01	36.1503113198914
1989-10-01	36.0287869538879
1990-01-01	36.0862802090343
1990-04-01	34.8434008320686
1990-07-01	35.4517424967436
1990-10-01	35.3670747313221
1991-01-01	35.5217245733378
1991-04-01	34.3440269470154
1991-07-01	34.6380148375544
1991-10-01	34.0470576463736
1992-01-01	35.3184733455305
1992-04-01	34.0033453049173
1992-07-01	34.7161630779436
1992-10-01	33.5638734871987
1993-01-01	35.8483151442439
1993-04-01	34.2012784409183
1993-07-01	34.8684542156165
1993-10-01	34.0405119751422
1994-01-01	35.5239428121929
1994-04-01	33.5026168402626
1994-07-01	34.9018603803213
1994-10-01	34.7451535591797
1995-01-01	35.4613936445555
1995-04-01	33.9573228172680
1995-07-01	34.6042340891204
1995-10-01	34.8097881162360
1996-01-01	34.9700658834852
1996-04-01	33.6912915125169
1996-07-01	34.0103185750152
1996-10-01	34.0489463104211
1997-01-01	33.9467200951322
1997-04-01	32.7416373024515
1997-07-01	33.0819017774877
1997-10-01	33.2372045854048
1998-01-01	33.6893119087126
1998-04-01	32.8943500766632
1998-07-01	33.1665031530406
1998-10-01	33.4596656687799
1999-01-01	34.2478896322858
1999-04-01	33.0947549203075
1999-07-01	33.1373558914286
1999-10-01	33.3586431515510
2000-01-01	34.4642126896994
2000-04-01	32.6722981744178
2000-07-01	33.3166504658459
2000-10-01	33.2381882786609
2001-01-01	33.0852624076697
2001-04-01	32.4526118597063
2001-07-01	32.8973021570083
2001-10-01	32.2648543585133
2002-01-01	33.1797890087412
2002-04-01	32.6609381107328
2002-07-01	32.6217538223420
2002-10-01	31.8405633913597
2003-01-01	33.0688044897850
2003-04-01	31.6675315252673
2003-07-01	32.1496631248667
2003-10-01	31.8323075022507
2004-01-01	32.3813374649314
2004-04-01	31.6532492039614
2004-07-01	31.4017009176926
2004-10-01	31.8523223357852
2005-01-01	32.0443522523380
2005-04-01	30.6698044811495
2005-07-01	30.7691244123857
2005-10-01	31.1322003307014
2006-01-01	31.4943070348800
2006-04-01	30.2202755443214
2006-07-01	30.1993263673717
2006-10-01	30.4496751150891
2007-01-01	30.9603006765457
2007-04-01	29.1490357773803
2007-07-01	29.9389141958649
2007-10-01	29.2827327578183
2008-01-01	30.2424366354589
2008-04-01	29.3452214925995
2008-07-01	29.4290579129971
2008-10-01	28.8806627596594
2009-01-01	29.2526021245894
2009-04-01	28.9293716392766
2009-07-01	28.1135196111665
2009-10-01	28.2341098350990
2010-01-01	28.9002303792166
2010-04-01	28.2268073636236
2010-07-01	27.8262645606504
2010-10-01	28.0920308427534
2011-01-01	28.3818687370740
2011-04-01	27.3624025539970
2011-07-01	27.5721836429128
2011-10-01	27.7742240797294
2012-01-01	28.6061533424535
2012-04-01	27.2344844894428
2012-07-01	27.8320364871238
2012-10-01	27.3998710296763
2013-01-01	27.1255158938320
2013-04-01	26.0656417132534
2013-07-01	26.3594723045736
2013-10-01	25.4704927868542
2014-01-01	26.1696227755883
2014-04-01	25.4764927872764
2014-07-01	25.2022853709266
2014-10-01	24.5019051909015
2015-01-01	25.2307006075171
2015-04-01	24.8208025864285
2015-07-01	24.3751253938067
2015-10-01	24.2334423103588
2016-01-01	24.4148715607338
2016-04-01	23.8228023250428
2016-07-01	23.3529052032246
2016-10-01	23.0201316402229
2017-01-01	23.5196271007779
2017-04-01	22.5094263473804
2017-07-01	22.3618681913521
2017-10-01	21.5996773880257
2018-01-01	21.7145154627972
2018-04-01	21.1229544417836
2018-07-01	20.7222437875612