Quarter	Percent
1968-01-01	83.5605668748836
1968-04-01	86.3465201681002
1968-07-01	85.9332503234942
1968-10-01	86.3291323668682
1969-01-01	83.5703669720386
1969-04-01	86.4000000000000
1969-07-01	86.7131798257990
1969-10-01	86.9488536155203
1970-01-01	84.0068509003379
1970-04-01	85.8143389970990
1970-07-01	85.7023407561321
1970-10-01	84.6211379460400
1971-01-01	84.5877761235598
1971-04-01	86.3916495181223
1971-07-01	85.7633459659538
1971-10-01	85.0042844901457
1972-01-01	82.6714137698860
1972-04-01	86.0967184801382
1972-07-01	85.5184233076264
1972-10-01	83.9727195225916
1973-01-01	83.5603806740087
1973-04-01	85.0335133500242
1973-07-01	85.8354537743851
1973-10-01	86.4161949767184
1974-01-01	83.8846480067854
1974-04-01	84.5370081874989
1974-07-01	85.4840664000969
1974-10-01	84.7929757144588
1975-01-01	82.7548244768575
1975-04-01	83.8389522879208
1975-07-01	84.6476294149167
1975-10-01	83.9759249648748
1976-01-01	82.0925848960760
1976-04-01	83.4024644945698
1976-07-01	83.7902486735070
1976-10-01	83.2384213595365
1977-01-01	80.3475603753436
1977-04-01	82.3284933952452
1977-07-01	82.3343266638286
1977-10-01	82.4600686669652
1978-01-01	80.2728246652155
1978-04-01	81.9863341090921
1978-07-01	82.1265072219960
1978-10-01	82.1469089788410
1979-01-01	80.2366991426453
1979-04-01	82.6625183643388
1979-07-01	82.4731002537242
1979-10-01	82.2215505580642
1980-01-01	80.9451176816743
1980-04-01	83.5855737073172
1980-07-01	82.8584190857021
1980-10-01	82.1368123746172
1981-01-01	81.1500684205980
1981-04-01	82.4460653102414
1981-07-01	82.4068857883121
1981-10-01	81.1690754803259
1982-01-01	80.9327170454610
1982-04-01	81.5067277350369
1982-07-01	82.4287847714276
1982-10-01	80.7113406326407
1983-01-01	79.5269864225032
1983-04-01	81.9990892344672
1983-07-01	81.4284724402821
1983-10-01	80.4067279173792
1984-01-01	79.5248635607711
1984-04-01	80.1102274012315
1984-07-01	80.0858618794786
1984-10-01	79.4382125602651
1985-01-01	78.7551570766509
1985-04-01	80.3403128390276
1985-07-01	79.5598192367834
1985-10-01	78.8306483768602
1986-01-01	78.0200986564046
1986-04-01	79.5443488524947
1986-07-01	79.4173502025510
1986-10-01	78.6607501230388
1987-01-01	77.3950052809122
1987-04-01	79.2224520898205
1987-07-01	78.7894465116091
1987-10-01	78.7949209045795
1988-01-01	77.9975562519948
1988-04-01	79.2169049901660
1988-07-01	79.2123464126499
1988-10-01	78.7391060259496
1989-01-01	78.4378551268423
1989-04-01	79.7531161135471
1989-07-01	80.1959633030767
1989-10-01	80.4379995538941
1990-01-01	79.6805156588500
1990-04-01	80.8925846335918
1990-07-01	81.0412398862651
1990-10-01	81.5465262833684
1991-01-01	81.2959127628798
1991-04-01	82.2479055830734
1991-07-01	82.1906626983854
1991-10-01	82.9448539192213
1992-01-01	82.1493301399657
1992-04-01	82.2232536026279
1992-07-01	82.1749492119018
1992-10-01	82.8934289555362
1993-01-01	82.3608576221816
1993-04-01	81.9330689887228
1993-07-01	82.6931491838664
1993-10-01	81.4479357166736
1994-01-01	80.8683853459973
1994-04-01	81.5585872029971
1994-07-01	81.8100087507128
1994-10-01	80.8577596375874
1995-01-01	80.1165708961141
1995-04-01	81.1941853108760
1995-07-01	81.2161056726002
1995-10-01	81.3725490196078
1996-01-01	79.5916909841252
1996-04-01	80.5394526983482
1996-07-01	81.1263884081367
1996-10-01	81.7312550944943
1997-01-01	80.5672101014944
1997-04-01	81.8023405378891
1997-07-01	80.8123830482759
1997-10-01	80.4524114383269
1998-01-01	79.7620999657072
1998-04-01	80.0427120168176
1998-07-01	79.4939253114158
1998-10-01	79.7143456122686
1999-01-01	80.0670119464282
1999-04-01	79.1599127182045
1999-07-01	79.3524391044681
1999-10-01	79.3217535153019
2000-01-01	78.3313386412060
2000-04-01	77.9117541145056
2000-07-01	78.9916562369629
2000-10-01	78.7502972376365
2001-01-01	78.2819919338147
2001-04-01	77.4179903512296
2001-07-01	77.6546374729381
2001-10-01	76.8877480442473
2002-01-01	77.4772212114208
2002-04-01	76.6759528633650
2002-07-01	76.7141264522966
2002-10-01	76.9952045957596
2003-01-01	76.8156916885762
2003-04-01	76.9616570668673
2003-07-01	77.7913494427894
2003-10-01	78.1168179749419
2004-01-01	77.7347970603516
2004-04-01	78.1980008618456
2004-07-01	78.4598735380866
2004-10-01	78.6211081220366
2005-01-01	78.4817692145856
2005-04-01	78.8782000799641
2005-07-01	79.6859758003936
2005-10-01	78.7713450320186
2006-01-01	79.1732431719508
2006-04-01	80.4266874155113
2006-07-01	80.5054100828749
2006-10-01	80.0437213315232
2007-01-01	81.2588884351590
2007-04-01	81.4668108038336
2007-07-01	81.8376658125909
2007-10-01	81.5873464925395
2008-01-01	81.3952416295183
2008-04-01	81.4536340852130
2008-07-01	81.4988946375453
2008-10-01	81.6182722623569
2009-01-01	81.0103917921583
2009-04-01	79.7899258839636
2009-07-01	79.4777719953951
2009-10-01	79.6227389569633
2010-01-01	79.5799304473713
2010-04-01	79.1544752132574
2010-07-01	78.7953500629557
2010-10-01	78.9206604850922
2011-01-01	79.2469366175212
2011-04-01	79.5331310394318
2011-07-01	78.6656025550997
2011-10-01	79.4689315288592
2012-01-01	78.5398179152260
2012-04-01	78.6516438626496
2012-07-01	78.8404368418815
2012-10-01	79.4311773285134
2013-01-01	79.6305879601204
2013-04-01	79.4270243571791
2013-07-01	79.7922285873946
2013-10-01	80.6227638904822
2014-01-01	81.4347899779787
2014-04-01	81.2106563002845
2014-07-01	81.7929295025978
2014-10-01	81.9510595442961
2015-01-01	82.3334256180519
2015-04-01	81.9282673147134
2015-07-01	83.0974814691996
2015-10-01	82.8148871731065
2016-01-01	82.8030140053946
2016-04-01	83.5683302364978
2016-07-01	83.9693719026196
2016-10-01	84.0220430988155
2017-01-01	84.4021511955100
2017-04-01	84.5521642506666
2017-07-01	85.5458841397167
2017-10-01	85.7392825896763
2018-01-01	85.9846279511101
2018-04-01	86.6637117076871
2018-07-01	86.0166205309693