Quarter	Percent
1968-01-01	38.5524963465527
1968-04-01	33.4197779202815
1968-07-01	33.1912477941061
1968-10-01	35.0302083605520
1969-01-01	37.9977353858780
1969-04-01	33.2647840808907
1969-07-01	33.7777771299782
1969-10-01	35.5389958335260
1970-01-01	38.2155099933067
1970-04-01	34.0704670747976
1970-07-01	34.1467726352267
1970-10-01	36.7206761905885
1971-01-01	38.4575067918380
1971-04-01	33.7731568176396
1971-07-01	34.0748791823872
1971-10-01	35.5230865898570
1972-01-01	39.4464415063540
1972-04-01	35.0991531410988
1972-07-01	35.2662381051128
1972-10-01	37.1243919768268
1973-01-01	38.3013122248084
1973-04-01	35.8338028572806
1973-07-01	35.1579337044173
1973-10-01	35.4142581888247
1974-01-01	38.7013945363092
1974-04-01	35.8815379409196
1974-07-01	35.7387867358769
1974-10-01	37.2587699716542
1975-01-01	39.6678899460710
1975-04-01	36.0253062335797
1975-07-01	35.4835891545504
1975-10-01	37.5549541937788
1976-01-01	39.5009477254589
1976-04-01	36.0374370832557
1976-07-01	35.2399572712394
1976-10-01	37.5581709406839
1977-01-01	40.4546292511282
1977-04-01	36.4738532685561
1977-07-01	36.1199581957567
1977-10-01	37.2698422683744
1978-01-01	39.8586150442268
1978-04-01	35.6317736990198
1978-07-01	35.7728399005005
1978-10-01	36.8830733312707
1979-01-01	39.5069287260401
1979-04-01	35.3789404230276
1979-07-01	35.4579007452546
1979-10-01	36.9336927230706
1980-01-01	39.1460483217785
1980-04-01	34.9284190819346
1980-07-01	35.1140454077095
1980-10-01	37.6084504005041
1981-01-01	39.3597837030476
1981-04-01	35.6872769343066
1981-07-01	35.7759646994865
1981-10-01	37.5128701087878
1982-01-01	39.0163156913211
1982-04-01	35.2662448157134
1982-07-01	35.6867116563294
1982-10-01	37.2106657741476
1983-01-01	38.1067287950956
1983-04-01	34.9026575312682
1983-07-01	34.9341151710439
1983-10-01	36.4522060627997
1984-01-01	38.6523082412736
1984-04-01	35.6645003502782
1984-07-01	35.9857413131436
1984-10-01	37.2753141300339
1985-01-01	38.7342966968451
1985-04-01	35.0859505145220
1985-07-01	35.9213133520033
1985-10-01	37.5006000866047
1986-01-01	39.1806095299524
1986-04-01	36.3118603359322
1986-07-01	35.8274448856446
1986-10-01	36.8572679101573
1987-01-01	38.8148389180284
1987-04-01	35.9245115983925
1987-07-01	35.8277741409673
1987-10-01	36.6033180950822
1988-01-01	38.2202772876363
1988-04-01	36.1177902090019
1988-07-01	35.7792645570319
1988-10-01	36.9896262545393
1989-01-01	37.8856835469032
1989-04-01	35.4290178085298
1989-07-01	35.2342998949817
1989-10-01	35.6737257299994
1990-01-01	37.0329894475513
1990-04-01	34.3199849772311
1990-07-01	34.1744813731964
1990-10-01	34.7521333188375
1991-01-01	35.5793762980480
1991-04-01	33.1365585869774
1991-07-01	32.6835572351291
1991-10-01	33.7559464073123
1992-01-01	34.6658127685511
1992-04-01	33.5504453657614
1992-07-01	33.0074911638102
1992-10-01	33.3183177995340
1993-01-01	34.3389208251143
1993-04-01	32.8941687966806
1993-07-01	32.5934338998243
1993-10-01	34.0229584385123
1994-01-01	35.0481654863890
1994-04-01	33.1571218817426
1994-07-01	32.9663393783497
1994-10-01	34.2769365810840
1995-01-01	35.0392224068662
1995-04-01	32.9330145048169
1995-07-01	33.2176214284365
1995-10-01	33.7952485394529
1996-01-01	35.5323299991473
1996-04-01	33.1834484899721
1996-07-01	32.5849471492516
1996-10-01	32.9643734855046
1997-01-01	34.4026616974892
1997-04-01	32.5109870352559
1997-07-01	32.5270694191526
1997-10-01	33.0282717407981
1998-01-01	33.9207224161599
1998-04-01	32.2492820360711
1998-07-01	32.2978731541614
1998-10-01	33.1691806789154
1999-01-01	33.4285573125915
1999-04-01	32.3662295017111
1999-07-01	32.3170236635668
1999-10-01	33.2058429301652
2000-01-01	34.1428989484660
2000-04-01	33.3130904866303
2000-07-01	32.9268787514412
2000-10-01	33.6479411286909
2001-01-01	34.1850987307218
2001-04-01	34.0527497098492
2001-07-01	34.0572355685332
2001-10-01	34.4888524440800
2002-01-01	34.6475698450928
2002-04-01	34.3449121491013
2002-07-01	34.3777142897902
2002-10-01	34.5077939457412
2003-01-01	34.5959509531417
2003-04-01	34.1359867792199
2003-07-01	33.8890900293164
2003-10-01	33.7809047972261
2004-01-01	34.6820222712912
2004-04-01	33.8261413647674
2004-07-01	33.3699206107349
2004-10-01	33.7556535837648
2005-01-01	34.0903113397407
2005-04-01	33.2735836461687
2005-07-01	32.6610241782374
2005-10-01	33.5582661367226
2006-01-01	33.5226254042258
2006-04-01	32.3063453791624
2006-07-01	32.3835851675456
2006-10-01	32.3878576734120
2007-01-01	32.1478828956543
2007-04-01	31.5504931607027
2007-07-01	31.1236264653819
2007-10-01	31.1697449428320
2008-01-01	31.6948334779102
2008-04-01	30.5535363370724
2008-07-01	30.7852913617025
2008-10-01	31.0951041895355
2009-01-01	31.3401211530794
2009-04-01	30.8859504820168
2009-07-01	30.7417336907954
2009-10-01	31.2723425735158
2010-01-01	31.2689746057124
2010-04-01	31.0682752153107
2010-07-01	30.7955057246248
2010-10-01	31.2097626172507
2011-01-01	31.1369536774327
2011-04-01	30.3360795007805
2011-07-01	31.4151405804364
2011-10-01	31.2653109330969
2012-01-01	31.6218387378661
2012-04-01	31.8747406570052
2012-07-01	31.9798079820596
2012-10-01	31.3303583979537
2013-01-01	30.6788955388836
2013-04-01	30.9909053422108
2013-07-01	30.3231985498636
2013-10-01	29.8026770879354
2014-01-01	29.5785762307698
2014-04-01	29.0088195578734
2014-07-01	28.7188002857288
2014-10-01	28.5289605197352
2015-01-01	27.9639458327968
2015-04-01	28.1788508945037
2015-07-01	27.0041482474787
2015-10-01	27.2254366628791
2016-01-01	26.8806091204217
2016-04-01	26.7385349325397
2016-07-01	25.6791014677452
2016-10-01	25.9182091532902
2017-01-01	25.3490302047666
2017-04-01	25.0480970632885
2017-07-01	23.9390352393605
2017-10-01	23.9905101826713
2018-01-01	23.5664569480209
2018-04-01	23.0937699188564
2018-07-01	22.7082518329332