Quarter	Percent
1968-01-01	52.6144024845531
1968-04-01	57.6234013599071
1968-07-01	56.6685330764217
1968-10-01	55.6164269988055
1969-01-01	52.4134618620695
1969-04-01	56.8058604175306
1969-07-01	56.0611699913932
1969-10-01	55.1649017892076
1970-01-01	52.2065996595153
1970-04-01	56.6594719996318
1970-07-01	55.8794140982803
1970-10-01	54.1300249998799
1971-01-01	51.7108770258259
1971-04-01	54.3469664795410
1971-07-01	54.1155832487978
1971-10-01	53.2461845026701
1972-01-01	50.7194556935633
1972-04-01	53.6973239497468
1972-07-01	53.9082826362561
1972-10-01	54.0069619370122
1973-01-01	52.4804751362978
1973-04-01	54.5041239400822
1973-07-01	54.3877751671701
1973-10-01	54.3634768644092
1974-01-01	51.3395503277065
1974-04-01	53.9231030666662
1974-07-01	52.9095786048477
1974-10-01	51.9712754704640
1975-01-01	49.4286029227268
1975-04-01	52.7725216819879
1975-07-01	52.9073086082047
1975-10-01	51.7233065557269
1976-01-01	49.9600097861341
1976-04-01	52.8354389257000
1976-07-01	53.4305761989792
1976-10-01	52.5899801977779
1977-01-01	50.9623226715684
1977-04-01	54.6364960217022
1977-07-01	54.4774988742472
1977-10-01	53.9473684210526
1978-01-01	52.2314031480631
1978-04-01	55.6788955749001
1978-07-01	55.1636931599106
1978-10-01	55.3162760336075
1979-01-01	53.4877981902934
1979-04-01	56.1687964066684
1979-07-01	55.8094969870858
1979-10-01	55.9300361034086
1980-01-01	54.0541427467365
1980-04-01	56.6369895173382
1980-07-01	56.3286393011480
1980-10-01	56.1368836339001
1981-01-01	54.0328252032520
1981-04-01	56.8143172815534
1981-07-01	56.6700507301298
1981-10-01	57.4558915664698
1982-01-01	55.8067954583792
1982-04-01	57.5847280765761
1982-07-01	57.1176170998215
1982-10-01	57.8288686441524
1983-01-01	56.8081042820535
1983-04-01	58.8608371151016
1983-07-01	58.9299455277891
1983-10-01	58.5632450734531
1984-01-01	56.8092072068596
1984-04-01	59.2888026912447
1984-07-01	59.4037407252943
1984-10-01	59.5197783071668
1985-01-01	57.7738326378683
1985-04-01	59.8220556361742
1985-07-01	59.9107715354165
1985-10-01	59.4490774006183
1986-01-01	58.3144219380731
1986-04-01	60.4408360587234
1986-07-01	60.0483537574620
1986-10-01	59.6688191847323
1987-01-01	58.4552599082648
1987-04-01	60.9258201501036
1987-07-01	60.6572069362271
1987-10-01	60.5248111209504
1988-01-01	59.6378982049770
1988-04-01	62.0390800332332
1988-07-01	61.4599100786762
1988-10-01	61.1089410878344
1989-01-01	60.7029448469479
1989-04-01	63.1791114222124
1989-07-01	62.5622732108265
1989-10-01	62.6959298129814
1990-01-01	62.5479429463726
1990-04-01	63.7659675110989
1990-07-01	63.2367484068060
1990-10-01	63.4105118548114
1991-01-01	63.2265169871907
1991-04-01	64.2100548279247
1991-07-01	63.9805576873881
1991-10-01	64.6327972262881
1992-01-01	63.2473028316629
1992-04-01	64.7040505282779
1992-07-01	63.9310024880809
1992-10-01	64.9546569957646
1993-01-01	62.5813901343976
1993-04-01	64.2673220627778
1993-07-01	63.5287583811693
1993-10-01	64.2320965459185
1994-01-01	62.6110530750701
1994-04-01	64.7347114900269
1994-07-01	63.2512595954886
1994-10-01	63.4222615359103
1995-01-01	62.6296359668196
1995-04-01	64.0838015697918
1995-07-01	63.4011742597733
1995-10-01	63.1211617219075
1996-01-01	63.0605376130181
1996-04-01	64.2368604140684
1996-07-01	63.9460322884511
1996-10-01	63.9194353113847
1997-01-01	63.9355237307988
1997-04-01	64.9782070454993
1997-07-01	64.8033027087632
1997-10-01	64.5999153068974
1998-01-01	64.1241659429505
1998-04-01	64.4575356333423
1998-07-01	64.0644955811508
1998-10-01	63.8214677811984
1999-01-01	62.8197362962888
1999-04-01	63.8920139705816
1999-07-01	63.8445086514454
1999-10-01	63.9021814016609
2000-01-01	62.5546442704008
2000-04-01	64.2462346643615
2000-07-01	63.8084406340598
2000-10-01	64.0694357123518
2001-01-01	63.9542357659914
2001-04-01	64.3849181782896
2001-07-01	63.9067436072192
2001-10-01	64.5901457867093
2002-01-01	63.2823096882066
2002-04-01	63.7654244182385
2002-07-01	63.8701674247538
2002-10-01	64.8305777827152
2003-01-01	63.5200916990194
2003-04-01	64.8489098239810
2003-07-01	64.4887919673390
2003-10-01	65.0460558910399
2004-01-01	64.4952663166091
2004-04-01	65.1880572579063
2004-07-01	65.5659829787415
2004-10-01	65.3253746641682
2005-01-01	64.9296872345738
2005-04-01	66.2296757279559
2005-07-01	66.2163448966836
2005-10-01	65.8581571935029
2006-01-01	65.7994872432891
2006-04-01	67.0158034029960
2006-07-01	67.0075815448631
2006-10-01	66.9375345170619
2007-01-01	66.2611414626223
2007-04-01	68.1600663850364
2007-07-01	67.3791757171500
2007-10-01	68.1010537471335
2008-01-01	66.9730210377592
2008-04-01	67.6535330483192
2008-07-01	67.6626848145183
2008-10-01	68.3274226793497
2009-01-01	67.4390792154289
2009-04-01	67.4259741222416
2009-07-01	67.9717063943775
2009-10-01	68.1963890461297
2010-01-01	67.6269775995165
2010-04-01	68.1892296460365
2010-07-01	68.6568019060193
2010-10-01	68.6608329266234
2011-01-01	68.4207298028734
2011-04-01	69.2191169495079
2011-07-01	69.2617769910661
2011-10-01	69.3671099709900
2012-01-01	68.2980199707755
2012-04-01	69.5287392760199
2012-07-01	69.1327493515050
2012-10-01	69.7802286143935
2013-01-01	70.0585294909478
2013-04-01	70.8293546497289
2013-07-01	70.7783167543688
2013-10-01	71.8298913945016
2014-01-01	71.1901364938062
2014-04-01	71.6166324249006
2014-07-01	72.0538463840844
2014-10-01	73.0795364082690
2015-01-01	72.3729351644188
2015-04-01	72.5316563266709
2015-07-01	73.0699825910764
2015-10-01	73.3488147172843
2016-01-01	73.3266235621169
2016-04-01	73.5518213607522
2016-07-01	74.4092381084893
2016-10-01	74.7949435609512
2017-01-01	74.3207319627930
2017-04-01	75.1571858435797
2017-07-01	75.5416295874119
2017-10-01	76.3552797938572
2018-01-01	76.3599606796676
2018-04-01	76.9632013342456
2018-07-01	77.4157155432344