Quarter	Percent
1968-01-01	55.3972334795422
1968-04-01	60.7129236214008
1968-07-01	59.8466176604302
1968-10-01	57.3117243039829
1969-01-01	54.7171328983823
1969-04-01	59.3270729270729
1969-07-01	58.5219836716843
1969-10-01	56.2878609302213
1970-01-01	55.0625404053180
1970-04-01	59.5229414002480
1970-07-01	59.2481977550669
1970-10-01	56.9169029717635
1971-01-01	57.3038301570407
1971-04-01	61.7242803095773
1971-07-01	59.8548209844410
1971-10-01	57.8439343698541
1972-01-01	57.0633518890395
1972-04-01	59.7064724058387
1972-07-01	58.8071682216265
1972-10-01	55.7510371615677
1973-01-01	54.1926606209738
1973-04-01	57.7785008947354
1973-07-01	56.4357484330939
1973-10-01	53.4622771012526
1974-01-01	52.3733985337674
1974-04-01	55.3697291234909
1974-07-01	53.1995452897296
1974-10-01	51.1515529153736
1975-01-01	48.7407615146438
1975-04-01	51.2903211452118
1975-07-01	50.4638107238345
1975-10-01	50.4686196214797
1976-01-01	48.7606989471850
1976-04-01	49.4264160441961
1976-07-01	48.7673788101448
1976-10-01	46.5286144290309
1977-01-01	45.4582443930333
1977-04-01	46.7665489849956
1977-07-01	46.9942960696355
1977-10-01	44.6525109939744
1978-01-01	44.0251229926159
1978-04-01	47.7729159148322
1978-07-01	44.7984845082620
1978-10-01	43.3660362605646
1979-01-01	41.9434194341943
1979-04-01	46.1942589549952
1979-07-01	44.5547950693628
1979-10-01	42.9099428554265
1980-01-01	40.9809830334912
1980-04-01	44.3528752064636
1980-07-01	43.8643210789958
1980-10-01	42.7588996763754
1981-01-01	41.6749023849756
1981-04-01	45.3921720274589
1981-07-01	44.2891525100114
1981-10-01	42.3661084397281
1982-01-01	41.0105949470253
1982-04-01	45.3266713667618
1982-07-01	43.7946414527250
1982-10-01	43.4413405728812
1983-01-01	42.5363354620579
1983-04-01	46.3498224043777
1983-07-01	44.2347312387391
1983-10-01	43.2231435787454
1984-01-01	41.6400569168543
1984-04-01	45.2196772262731
1984-07-01	43.9083999234735
1984-10-01	42.9512221442832
1985-01-01	40.9815583695975
1985-04-01	44.0860003015028
1985-07-01	43.3061081533890
1985-10-01	42.3050335839197
1986-01-01	40.8217335342575
1986-04-01	44.5363774553453
1986-07-01	43.5729991981847
1986-10-01	42.2710027100271
1987-01-01	40.2195926737144
1987-04-01	44.1191910034166
1987-07-01	43.4351181083071
1987-10-01	41.8621674190089
1988-01-01	39.5667993487294
1988-04-01	44.5992577837689
1988-07-01	42.8497616627751
1988-10-01	41.8956019760631
1989-01-01	40.0406855763642
1989-04-01	44.3705097101602
1989-07-01	43.1325318292475
1989-10-01	42.5952496879708
1990-01-01	40.7963460866468
1990-04-01	45.3254461120250
1990-07-01	44.4150896101340
1990-10-01	44.1270607741417
1991-01-01	42.4374333310777
1991-04-01	46.8869880625303
1991-07-01	46.7266174518118
1991-10-01	45.3077699293643
1992-01-01	44.3211995271916
1992-04-01	47.7760753709482
1992-07-01	47.9790832896539
1992-10-01	47.0806126340530
1993-01-01	45.0762846804386
1993-04-01	48.6025903203817
1993-07-01	48.5154104513091
1993-10-01	48.4619588062211
1994-01-01	45.7920623617209
1994-04-01	49.6215674902700
1994-07-01	49.2233340020541
1994-10-01	47.8559380187796
1995-01-01	45.9988792393456
1995-04-01	49.0403217091789
1995-07-01	49.3676446120570
1995-10-01	47.9398184097957
1996-01-01	47.1093253622812
1996-04-01	50.3569651758439
1996-07-01	50.0535116616716
1996-10-01	48.5552349214831
1997-01-01	47.7511559478773
1997-04-01	50.9370756244941
1997-07-01	50.6112990696037
1997-10-01	48.5846448502843
1998-01-01	46.6948199626314
1998-04-01	50.2652774900358
1998-07-01	49.8470524115933
1998-10-01	48.8865461763399
1999-01-01	46.4211139490075
1999-04-01	49.5923703689019
1999-07-01	48.2883505603815
1999-10-01	47.0500262401970
2000-01-01	45.5100047379173
2000-04-01	49.3395869727111
2000-07-01	47.6101177270125
2000-10-01	47.2763117669190
2001-01-01	44.6452283151655
2001-04-01	48.8041372111741
2001-07-01	47.2931213632585
2001-10-01	45.6714108716297
2002-01-01	44.4227856711974
2002-04-01	47.4725881458047
2002-07-01	47.6495102143106
2002-10-01	44.7779513081599
2003-01-01	44.0997560406639
2003-04-01	47.0427072193514
2003-07-01	45.5544933309783
2003-10-01	44.4139777761552
2004-01-01	41.9955030781240
2004-04-01	45.1898080705316
2004-07-01	45.3274339899416
2004-10-01	44.3735853221135
2005-01-01	41.3479972814168
2005-04-01	45.0185659089769
2005-07-01	45.7814499952240
2005-10-01	45.7404613890196
2006-01-01	43.0775120306216
2006-04-01	45.8800128568259
2006-07-01	45.4082321389503
2006-10-01	44.2223338450942
2007-01-01	42.9474372255932
2007-04-01	47.5094372629339
2007-07-01	45.2048567822808
2007-10-01	44.3128721533957
2008-01-01	41.3279097325042
2008-04-01	46.5755322157198
2008-07-01	45.4459493170651
2008-10-01	43.9098406408956
2009-01-01	40.9863854380791
2009-04-01	44.7826065102722
2009-07-01	43.2160769775936
2009-10-01	41.2817591417070
2010-01-01	40.2861532134715
2010-04-01	43.4405308831036
2010-07-01	42.6438256414177
2010-10-01	41.6138904359480
2011-01-01	39.5521228115430
2011-04-01	44.7228431703319
2011-07-01	42.6150568846856
2011-10-01	41.0713960439488
2012-01-01	39.3893009552795
2012-04-01	43.0305355506964
2012-07-01	42.4863400336506
2012-10-01	41.0704822469528
2013-01-01	39.7870413707495
2013-04-01	43.4666666666667
2013-07-01	42.7061225162833
2013-10-01	40.7803261033598
2014-01-01	40.2255276907540
2014-04-01	43.6227224008574
2014-07-01	43.3950381535027
2014-10-01	41.4385399892646
2015-01-01	40.4403234464010
2015-04-01	43.0717884785206
2015-07-01	42.8491907504151
2015-10-01	43.2712338602641
2016-01-01	41.6939638043012
2016-04-01	46.2809122867290
2016-07-01	44.5397738203204
2016-10-01	44.9252136752137
2017-01-01	41.8308696516196
2017-04-01	46.4149541001703
2017-07-01	45.0099316089930
2017-10-01	43.7664340998923
2018-01-01	43.8959660297240
2018-04-01	48.4372598570417
2018-07-01	47.6671528993510