Quarter	Percent
1968-01-01	47.1906060704006
1968-04-01	41.3661923622317
1968-07-01	42.5184803595280
1968-10-01	45.4647031914931
1969-01-01	47.7386918446351
1969-04-01	42.6649442172827
1969-07-01	43.2606591511721
1969-10-01	46.0685483870968
1970-01-01	47.1385492963941
1970-04-01	42.6320509602146
1970-07-01	42.7463948051328
1970-10-01	44.9940438538639
1971-01-01	45.4272402408243
1971-04-01	41.3457256835418
1971-07-01	43.1530290602519
1971-10-01	45.7338855488084
1972-01-01	46.4154936087324
1972-04-01	44.2145616363603
1972-07-01	45.0754870549462
1972-10-01	46.9881226546305
1973-01-01	48.0493152410431
1973-04-01	45.4559142024566
1973-07-01	46.3962935155374
1973-10-01	48.8325376226466
1974-01-01	51.1984730104787
1974-04-01	47.7649433897475
1974-07-01	49.5651433802886
1974-10-01	51.1630935446110
1975-01-01	53.6261354565676
1975-04-01	50.5457412888071
1975-07-01	51.4734908135409
1975-10-01	52.4053089248549
1976-01-01	53.9248743251866
1976-04-01	52.6107689869384
1976-07-01	52.9886631303954
1976-10-01	54.9400177490605
1977-01-01	55.9186970906309
1977-04-01	53.1977947853620
1977-07-01	53.7000600476792
1977-10-01	55.7070468846727
1978-01-01	56.7983117987563
1978-04-01	52.7300019837924
1978-07-01	54.5759238880283
1978-10-01	56.6049966951150
1979-01-01	57.8188099707968
1979-04-01	53.8624306086786
1979-07-01	54.6891546800083
1979-10-01	57.1094556674757
1980-01-01	59.4090226752514
1980-04-01	55.1506179764401
1980-07-01	54.6791647070349
1980-10-01	56.9130073100754
1981-01-01	58.4340294319628
1981-04-01	54.1704793171308
1981-07-01	55.2304629241649
1981-10-01	57.4593262509983
1982-01-01	59.0020568104145
1982-04-01	54.8050480711051
1982-07-01	55.7846434244114
1982-10-01	56.5210431019254
1983-01-01	57.6305449458605
1983-04-01	53.3943025377094
1983-07-01	55.2059827484777
1983-10-01	56.6283373509304
1984-01-01	58.4881420243637
1984-04-01	54.3202330554857
1984-07-01	54.9336422053041
1984-10-01	56.7267222110280
1985-01-01	58.4516314600168
1985-04-01	55.7170447064278
1985-07-01	56.2435300108483
1985-10-01	57.4197394841496
1986-01-01	58.3619900906205
1986-04-01	55.1942495142955
1986-07-01	55.7287004631526
1986-10-01	57.5103894875461
1987-01-01	59.3290183927113
1987-04-01	55.4576605054858
1987-07-01	56.2270088316180
1987-10-01	57.7228913790029
1988-01-01	59.6479463208975
1988-04-01	55.1655704903737
1988-07-01	56.4735721893046
1988-10-01	57.6449601215878
1989-01-01	59.1556541771492
1989-04-01	54.6645825021297
1989-07-01	55.8691798267770
1989-10-01	56.9478875328282
1990-01-01	58.6931999061372
1990-04-01	53.9690834673349
1990-07-01	54.8175809756593
1990-10-01	55.3948804470400
1991-01-01	57.3984091137418
1991-04-01	52.4824169162239
1991-07-01	53.2725430154640
1991-10-01	54.3856406386594
1992-01-01	55.7660311341066
1992-04-01	51.5477596780338
1992-07-01	52.4703738293153
1992-10-01	53.5466134190975
1993-01-01	55.5425899853142
1993-04-01	51.3692567805082
1993-07-01	51.8795381270412
1993-10-01	52.4493637958856
1994-01-01	54.5764256705661
1994-04-01	50.6525387399956
1994-07-01	51.4161050455276
1994-10-01	52.5784285956185
1995-01-01	54.1995661284998
1995-04-01	51.1451750077953
1995-07-01	51.3153153153153
1995-10-01	52.5284649302400
1996-01-01	53.5692206149381
1996-04-01	49.8897291692419
1996-07-01	50.4801881309634
1996-10-01	52.7233736269188
1997-01-01	53.3597154428017
1997-04-01	49.9336893892946
1997-07-01	50.1615623446941
1997-10-01	52.1736130359817
1998-01-01	53.5708453687897
1998-04-01	49.9901256286197
1998-07-01	50.7911248937695
1998-10-01	52.2380740966196
1999-01-01	54.0151240668463
1999-04-01	50.5181766320913
1999-07-01	52.1564285087327
1999-10-01	53.7992684252676
2000-01-01	54.8179243260322
2000-04-01	51.2841802465956
2000-07-01	52.6036736590386
2000-10-01	52.8203001357092
2001-01-01	54.9822966497045
2001-04-01	51.5098396693229
2001-07-01	52.9323700521964
2001-10-01	54.4833258591301
2002-01-01	56.2150112940231
2002-04-01	52.8766837752558
2002-07-01	53.1652675727638
2002-10-01	55.6223522064612
2003-01-01	56.7204585399912
2003-04-01	53.3839647469659
2003-07-01	54.3413874768941
2003-10-01	55.8908960554414
2004-01-01	57.6786377441552
2004-04-01	54.6930610347320
2004-07-01	54.4433046533197
2004-10-01	55.9469327812765
2005-01-01	57.9423758116013
2005-04-01	53.9685189775980
2005-07-01	54.0840790568882
2005-10-01	54.9212045123576
2006-01-01	56.8564518087338
2006-04-01	53.4623967941522
2006-07-01	54.2889075793490
2006-10-01	55.6732048908845
2007-01-01	56.9987152170101
2007-04-01	52.6874439008219
2007-07-01	54.8830717234214
2007-10-01	55.9451204140905
2008-01-01	57.7158876425723
2008-04-01	53.0480874378864
2008-07-01	55.1757874138050
2008-10-01	56.2438252389487
2009-01-01	58.2735342058654
2009-04-01	54.1383275292322
2009-07-01	55.9800236873587
2009-10-01	57.5355373219088
2010-01-01	59.0233247048274
2010-04-01	55.7881957814572
2010-07-01	56.8001958976044
2010-10-01	57.2525742096865
2011-01-01	59.0356778185861
2011-04-01	54.7567090120282
2011-07-01	57.0826727110937
2011-10-01	58.7003018620812
2012-01-01	60.5493390379025
2012-04-01	56.7919518282054
2012-07-01	56.9112731133358
2012-10-01	58.8005037408422
2013-01-01	59.8527808069554
2013-04-01	55.7430083144369
2013-07-01	56.8339914737471
2013-10-01	57.8818893968024
2014-01-01	59.1982251346291
2014-04-01	55.8178588619738
2014-07-01	56.3032709907429
2014-10-01	57.7715368564106
2015-01-01	59.7633538897757
2015-04-01	55.8548035423064
2015-07-01	56.8440249863301
2015-10-01	56.7655208312689
2016-01-01	57.7834706201640
2016-04-01	54.1187988536448
2016-07-01	54.8501064678005
2016-10-01	55.4062006359279
2017-01-01	57.7687151740289
2017-04-01	53.5627670594535
2017-07-01	54.2477574025630
2017-10-01	55.8919604856523
2018-01-01	54.9030177718702
2018-04-01	51.0765208781796
2018-07-01	51.4868036774958