Quarter	Percent
1978-04-01	26.7421592625847
1978-07-01	27.8933478776727
1978-10-01	29.3953168051988
1979-01-01	30.1193094519089
1979-04-01	30.1662666161301
1979-07-01	29.8047398074446
1979-10-01	30.1739451001791
1980-01-01	30.8124930736751
1980-04-01	30.5470752609107
1980-07-01	30.7906272383744
1980-10-01	31.7562358469092
1981-01-01	32.4534724941217
1981-04-01	32.6261438131991
1981-07-01	31.7128297176930
1981-10-01	32.7811290220989
1982-01-01	33.3786321457433
1982-04-01	34.4019259106924
1982-07-01	34.3532740694069
1982-10-01	35.0657726703654
1983-01-01	36.2777036323499
1983-04-01	36.7947100005688
1983-07-01	37.0985831962884
1983-10-01	37.5178827564528
1984-01-01	37.3936273408134
1984-04-01	37.3510102618128
1984-07-01	37.9854501541939
1984-10-01	38.5320783835582
1985-01-01	38.9999391610824
1985-04-01	39.6483582775282
1985-07-01	38.6829557428152
1985-10-01	37.1655556960096
1986-01-01	38.2181014519713
1986-04-01	37.7693931435624
1986-07-01	38.4158962913091
1986-10-01	37.8172763734032
1987-01-01	38.3955840184637
1987-04-01	38.3321054356876
1987-07-01	39.3576208444900
1987-10-01	38.4362770291957
1988-01-01	37.9035611644642
1988-04-01	37.7581865171359
1988-07-01	38.5142562017255
1988-10-01	39.1512471489230
1989-01-01	38.2203984611769
1989-04-01	37.2634753403916
1989-07-01	36.8952148084215
1989-10-01	37.1023697263374
1990-01-01	38.5839461873226
1990-04-01	37.4904897966230
1990-07-01	36.2608556241113
1990-10-01	36.3313077705537
1991-01-01	37.5988190013408
1991-04-01	38.1407334700531
1991-07-01	38.9881765067445
1991-10-01	38.3285824874020
1992-01-01	38.1941870720106
1992-04-01	38.4564476799034
1992-07-01	38.0858835092036
1992-10-01	39.0239454249858
1993-01-01	40.0705163694029
1993-04-01	39.8584722548182
1993-07-01	40.1568960240316
1993-10-01	38.5995994140853
1994-01-01	38.2772127312492
1994-04-01	38.3462106457264
1994-07-01	38.8300693031687
1994-10-01	38.9448466277637
1995-01-01	38.7116841662080
1995-04-01	38.6216186649015
1995-07-01	38.4598206638457
1995-10-01	38.5582156631956
1996-01-01	39.6781684783354
1996-04-01	39.5026935567727
1996-07-01	39.4146545717180
1996-10-01	39.4481459341750
1997-01-01	39.5183782622784
1997-04-01	39.8937682569752
1997-07-01	39.9769502982881
1997-10-01	39.6774907616732
1998-01-01	40.3101257627903
1998-04-01	39.0594065920134
1998-07-01	38.8975340699093
1998-10-01	39.4936373554088
1999-01-01	40.0273815418041
1999-04-01	39.8814623594117
1999-07-01	38.9918659436417
1999-10-01	39.1019743454502
2000-01-01	40.0072231197547
2000-04-01	39.1944954193521
2000-07-01	38.4631245530014
2000-10-01	38.9489167922637
2001-01-01	40.1542950801556
2001-04-01	39.3010959266379
2001-07-01	39.4396503457372
2001-10-01	38.9534594812913
2002-01-01	38.5857927926404
2002-04-01	37.6519978533266
2002-07-01	38.3151175945509
2002-10-01	37.5028048267344
2003-01-01	36.7593368568002
2003-04-01	36.6255944520626
2003-07-01	36.4089346235837
2003-10-01	36.2680157404526
2004-01-01	36.4406937249599
2004-04-01	34.9738986164272
2004-07-01	34.8324559572212
2004-10-01	35.1830122508603
2005-01-01	35.1685200418265
2005-04-01	33.5719319899213
2005-07-01	33.4174005237834
2005-10-01	33.0469274694954
2006-01-01	33.4318371614681
2006-04-01	32.6917528016656
2006-07-01	31.9298088009144
2006-10-01	32.7923891771954
2007-01-01	32.8417814429991
2007-04-01	31.7570231543449
2007-07-01	32.0014371605886
2007-10-01	32.7964022551738
2008-01-01	33.7717702345890
2008-04-01	31.8335252217232
2008-07-01	31.8034293563513
2008-10-01	32.0259446962886
2009-01-01	31.2049145219991
2009-04-01	30.6923547985192
2009-07-01	30.4864937242595
2009-10-01	30.4447058870102
2010-01-01	29.7061320732206
2010-04-01	28.8704084841608
2010-07-01	28.3056295517646
2010-10-01	28.2311712636454
2011-01-01	28.1028059222088
2011-04-01	27.9930290039644
2011-07-01	28.4285910247462
2011-10-01	28.8146343344065
2012-01-01	29.2687020044808
2012-04-01	28.2078511231597
2012-07-01	27.9513868525153
2012-10-01	27.5738743114227
2013-01-01	27.9956984272333
2013-04-01	27.5679144038590
2013-07-01	27.7499393346849
2013-10-01	28.2527722348416
2014-01-01	28.2328051413173
2014-04-01	27.8203491879667
2014-07-01	27.3837190213168
2014-10-01	27.8995275148517
2015-01-01	27.7624276136304
2015-04-01	26.7520928916943
2015-07-01	27.3326750269737
2015-10-01	27.0351018529989
2016-01-01	27.1360497741116
2016-04-01	27.5594625812274
2016-07-01	28.9859235052909
2016-10-01	28.5569125522091
2017-01-01	28.6733935308420
2017-04-01	27.2110549026214
2017-07-01	26.8790895180738
2017-10-01	26.2029033938573
2018-01-01	26.3430764128133
2018-04-01	27.1176778895096
2018-07-01	26.9164572346637