Quarter	Percent
1968-01-01	49.7978855808882
1968-04-01	43.5027211021641
1968-07-01	44.8881502086364
1968-10-01	48.2518743964498
1969-01-01	50.2360989763005
1969-04-01	44.7454973023789
1969-07-01	45.0593524072102
1969-10-01	48.4890101334728
1970-01-01	49.4061645120148
1970-04-01	44.8101049238598
1970-07-01	44.7711466774143
1970-10-01	46.9454099792073
1971-01-01	48.2564069245612
1971-04-01	44.4924387904081
1971-07-01	46.2588809175107
1971-10-01	49.3256484432695
1972-01-01	50.0417366445900
1972-04-01	48.2165891555874
1972-07-01	49.0545424807647
1972-10-01	49.7376353390467
1973-01-01	50.2826485373748
1973-04-01	48.6633321024281
1973-07-01	49.2158367379063
1973-10-01	51.0919789681587
1974-01-01	54.7548514541806
1974-04-01	50.9058763297971
1974-07-01	52.3481171371627
1974-10-01	53.5158296754850
1975-01-01	56.0496788485331
1975-04-01	52.5029778073220
1975-07-01	53.4239835866516
1975-10-01	55.3788615693790
1976-01-01	56.6700633692108
1976-04-01	54.7134158379056
1976-07-01	54.8856186857472
1976-10-01	56.4594027265620
1977-01-01	57.3013214371130
1977-04-01	53.0798145035497
1977-07-01	54.3552970072628
1977-10-01	56.0331863754891
1978-01-01	57.5993287276473
1978-04-01	53.2686286119690
1978-07-01	53.9511160343389
1978-10-01	56.6173814128940
1979-01-01	57.6399626154087
1979-04-01	53.9440203562341
1979-07-01	53.9246257489074
1979-10-01	57.1055330469434
1980-01-01	59.7797982744742
1980-04-01	54.6349128127166
1980-07-01	53.1833463052860
1980-10-01	56.5353722238321
1981-01-01	58.5472543075658
1981-04-01	53.7544546869647
1981-07-01	54.7311352789931
1981-10-01	57.2343775360598
1982-01-01	59.0148353289762
1982-04-01	54.9183230867922
1982-07-01	55.3237189405037
1982-10-01	56.4582881509711
1983-01-01	57.7795523675206
1983-04-01	53.1092497414846
1983-07-01	54.6004834168050
1983-10-01	56.4914587800340
1984-01-01	58.6385234999082
1984-04-01	53.8216894910611
1984-07-01	53.7231742604180
1984-10-01	56.3270798510190
1985-01-01	57.8817299205649
1985-04-01	55.5330823319565
1985-07-01	55.7940111577810
1985-10-01	57.1540256565616
1986-01-01	57.5392563289125
1986-04-01	54.9113873508658
1986-07-01	55.0182689851298
1986-10-01	57.2642742891756
1987-01-01	58.8514770136884
1987-04-01	55.0135987356325
1987-07-01	55.8350256314613
1987-10-01	57.2829986695533
1988-01-01	58.8402646430948
1988-04-01	54.9570071454911
1988-07-01	55.7691272334351
1988-10-01	57.1476978985915
1989-01-01	58.2603831060912
1989-04-01	53.6324287165380
1989-07-01	54.8574004139767
1989-10-01	56.4473683168489
1990-01-01	58.1703575879590
1990-04-01	53.2079661240253
1990-07-01	54.0068191782462
1990-10-01	54.8916699515412
1991-01-01	57.2467790425537
1991-04-01	51.7674592706177
1991-07-01	53.2500386089161
1991-10-01	54.0824552479950
1992-01-01	55.8573719520578
1992-04-01	50.8385593087134
1992-07-01	52.8881252618722
1992-10-01	54.2213297305521
1993-01-01	56.1571215267010
1993-04-01	51.3223606836899
1993-07-01	52.2765065145009
1993-10-01	53.4050976951041
1994-01-01	54.9607710683587
1994-04-01	50.9583173371708
1994-07-01	52.0517825591612
1994-10-01	53.0541143722885
1995-01-01	54.4112853626237
1995-04-01	51.3771579184253
1995-07-01	52.0740740740741
1995-10-01	53.0021446836592
1996-01-01	54.2648864498159
1996-04-01	50.1496856811817
1996-07-01	51.0411730042695
1996-10-01	54.0315976899792
1997-01-01	54.5853604795729
1997-04-01	50.8471184196978
1997-07-01	50.9725226699986
1997-10-01	52.9877261085753
1998-01-01	53.8496026649287
1998-04-01	50.2380956848147
1998-07-01	51.5224847460043
1998-10-01	53.4209413715500
1999-01-01	54.4938763647818
1999-04-01	50.6745495756551
1999-07-01	52.6649590895607
1999-10-01	54.7115549416330
2000-01-01	55.1628194497458
2000-04-01	51.8741474203537
2000-07-01	52.8288199059956
2000-10-01	52.9012831442499
2001-01-01	54.5905549796600
2001-04-01	51.8378354797983
2001-07-01	53.1903122201468
2001-10-01	54.7129815339927
2002-01-01	56.8847393831705
2002-04-01	53.2890235268834
2002-07-01	53.9980862912134
2002-10-01	56.0869472607918
2003-01-01	57.5062823410456
2003-04-01	53.8282556079547
2003-07-01	54.2353517730792
2003-10-01	56.2522980159849
2004-01-01	57.3364034742054
2004-04-01	54.5746652185449
2004-07-01	54.1296979813778
2004-10-01	56.3102406839502
2005-01-01	57.2027185118858
2005-04-01	52.8765996444621
2005-07-01	53.9687194113478
2005-10-01	55.5832881325288
2006-01-01	56.7098765888960
2006-04-01	52.8218426317703
2006-07-01	53.9695873509024
2006-10-01	55.5625148069178
2007-01-01	56.9628548140606
2007-04-01	52.9476464139695
2007-07-01	55.0497739233504
2007-10-01	56.1894312549120
2008-01-01	56.6592732420953
2008-04-01	52.6510453438154
2008-07-01	55.7277403463015
2008-10-01	56.3245092303692
2009-01-01	57.4045949196986
2009-04-01	52.8366367081324
2009-07-01	55.1040339350094
2009-10-01	56.2626893028581
2010-01-01	58.1732628170830
2010-04-01	54.7695605573419
2010-07-01	56.1555322403386
2010-10-01	56.0729549388882
2011-01-01	57.3025094665552
2011-04-01	54.0573007726581
2011-07-01	56.5594785810324
2011-10-01	58.5581285401268
2012-01-01	60.5734413332785
2012-04-01	56.5584774539998
2012-07-01	56.3268733850129
2012-10-01	58.5420144685587
2013-01-01	59.2628116324190
2013-04-01	55.1396055594902
2013-07-01	56.4387709289633
2013-10-01	56.5338728083826
2014-01-01	58.6042481875815
2014-04-01	55.2557712549281
2014-07-01	56.0573679199611
2014-10-01	57.1099448411674
2015-01-01	60.0230386111828
2015-04-01	54.8787462933983
2015-07-01	56.6182405165456
2015-10-01	56.8044203542784
2016-01-01	57.2077542133080
2016-04-01	54.5406213449102
2016-07-01	54.2323171489480
2016-10-01	55.7880447771182
2017-01-01	57.3444122874983
2017-04-01	53.5391388117639
2017-07-01	53.4566261800663
2017-10-01	55.5052113792979
2018-01-01	53.5996156358720
2018-04-01	50.5893670599553
2018-07-01	50.5631537059471