Quarter	Percent
1968-01-01	16.5151839109191
1968-04-01	14.3571397715793
1968-07-01	14.3940121956213
1968-10-01	15.1826986048234
1969-01-01	16.5478200191232
1969-04-01	14.3976263327747
1969-07-01	14.6099240150839
1969-10-01	15.4655829519942
1970-01-01	16.1668724242141
1970-04-01	14.4722353160402
1970-07-01	14.6046205047908
1970-10-01	15.2351554448664
1971-01-01	15.2131634874779
1971-04-01	13.6872296730850
1971-07-01	14.3889181713695
1971-10-01	14.7734744474173
1972-01-01	15.0774225611262
1972-04-01	13.7404813372367
1972-07-01	13.8822325176160
1972-10-01	14.7852363641584
1973-01-01	15.0371773432002
1973-04-01	13.6198132189049
1973-07-01	13.7912268135500
1973-10-01	14.4241165387028
1974-01-01	14.9151703333123
1974-04-01	13.7363352938160
1974-07-01	14.2078996584465
1974-10-01	14.4901307774090
1975-01-01	15.4520882899695
1975-04-01	14.4296061620490
1975-07-01	14.4279920165221
1975-10-01	14.1476674552724
1976-01-01	14.9589633903106
1976-04-01	14.3684155819911
1976-07-01	14.4670056707208
1976-10-01	14.8226127278285
1977-01-01	15.5385253043030
1977-04-01	14.8142165439342
1977-07-01	14.8679845327432
1977-10-01	15.2183620438894
1978-01-01	15.6086445123809
1978-04-01	14.3459941483661
1978-07-01	15.0518488209176
1978-10-01	15.3147961135175
1979-01-01	15.9741108698181
1979-04-01	14.4723708104928
1979-07-01	14.7329127175282
1979-10-01	15.2107210985307
1980-01-01	16.0257418130922
1980-04-01	14.9390403524791
1980-07-01	15.0439073204550
1980-10-01	15.3293085540654
1981-01-01	15.5933300289684
1981-04-01	14.6421006614591
1981-07-01	15.0615726904042
1981-10-01	15.7213776918066
1982-01-01	15.8864472890968
1982-04-01	14.6025847041567
1982-07-01	15.1783802092723
1982-10-01	15.3340805614519
1983-01-01	15.7169088123974
1983-04-01	14.5661882593702
1983-07-01	15.0719282000738
1983-10-01	15.5512577113832
1984-01-01	16.1119160374300
1984-04-01	15.1646560696304
1984-07-01	15.4532110973266
1984-10-01	15.8658281768287
1985-01-01	16.6557001760240
1985-04-01	15.6862542201631
1985-07-01	16.0815919226920
1985-10-01	16.5063289410827
1986-01-01	17.0626522345109
1986-04-01	16.0061449162671
1986-07-01	16.0429549039187
1986-10-01	16.7660402286610
1987-01-01	17.4525201048052
1987-04-01	16.3605691720306
1987-07-01	16.3336660595444
1987-10-01	16.9997766725134
1988-01-01	17.7469623430411
1988-04-01	16.5161897530964
1988-07-01	16.7360865031357
1988-10-01	17.2398081424475
1989-01-01	17.8109741078129
1989-04-01	16.4850866094059
1989-07-01	16.7795191974486
1989-10-01	17.0876050429955
1990-01-01	17.6158476019472
1990-04-01	16.3456075668585
1990-07-01	16.5502290595550
1990-10-01	16.4615891790185
1991-01-01	17.0127411829391
1991-04-01	15.8805747861226
1991-07-01	16.0723741053712
1991-10-01	16.1340532944573
1992-01-01	16.3867092338714
1992-04-01	15.6182767995786
1992-07-01	15.6911324378549
1992-10-01	15.5634176935549
1993-01-01	16.2755799702803
1993-04-01	15.2667787317206
1993-07-01	15.2662198546182
1993-10-01	15.3063122251422
1994-01-01	16.2508821453776
1994-04-01	15.1922229926312
1994-07-01	15.0970159674969
1994-10-01	15.5510008292026
1995-01-01	16.3303014980870
1995-04-01	15.2211220730469
1995-07-01	14.9017085031341
1995-10-01	15.1895199125696
1996-01-01	15.7824922930402
1996-04-01	14.6193515219221
1996-07-01	14.3753269258736
1996-10-01	14.7547277420758
1997-01-01	14.9908370897885
1997-04-01	14.0074778526185
1997-07-01	14.2900277409482
1997-10-01	14.7650223798073
1998-01-01	15.1653264207447
1998-04-01	14.1808257029108
1998-07-01	14.4069740766231
1998-10-01	14.5699520286161
1999-01-01	14.9590480064639
1999-04-01	14.2868667706614
1999-07-01	14.4533198528280
1999-10-01	14.6032894025697
2000-01-01	15.1714321135122
2000-04-01	14.3801705176886
2000-07-01	14.4790485664555
2000-10-01	14.4625612346089
2001-01-01	15.2412217689029
2001-04-01	14.4355511336677
2001-07-01	14.6571009797115
2001-10-01	15.0952292198382
2002-01-01	15.5612037464546
2002-04-01	14.9103827219747
2002-07-01	14.8727583608941
2002-10-01	15.2678543781203
2003-01-01	15.6326846064758
2003-04-01	15.0031405532640
2003-07-01	15.1588168643344
2003-10-01	15.2096855542345
2004-01-01	16.0434591317079
2004-04-01	15.3882743252734
2004-07-01	15.3803816267511
2004-10-01	15.5237445300459
2005-01-01	16.1145112814063
2005-04-01	15.4069975253695
2005-07-01	15.1620352187674
2005-10-01	15.2599927292079
2006-01-01	15.5607524456766
2006-04-01	14.7858404802582
2006-07-01	15.0237171023140
2006-10-01	15.1732574886821
2007-01-01	15.1715582907602
2007-04-01	14.2038287142311
2007-07-01	14.6135145689688
2007-10-01	14.7632797272923
2008-01-01	15.2338675450369
2008-04-01	14.2903653478237
2008-07-01	14.5812199121465
2008-10-01	14.7345803769592
2009-01-01	15.3424449704173
2009-04-01	14.6997334070703
2009-07-01	14.9312566747995
2009-10-01	15.2883099463457
2010-01-01	15.3389255660472
2010-04-01	14.7417230892390
2010-07-01	14.9736218817988
2010-10-01	15.2034443173543
2011-01-01	15.3631142575798
2011-04-01	14.3196379984199
2011-07-01	15.2396775294301
2011-10-01	15.4787084801014
2012-01-01	15.9291707340809
2012-04-01	15.3390211449359
2012-07-01	15.5120102019293
2012-10-01	15.6863001007542
2013-01-01	15.8555949379284
2013-04-01	15.0678617561021
2013-07-01	15.1712230666294
2013-10-01	15.3840713873349
2014-01-01	15.4600752258417
2014-04-01	14.6922437247273
2014-07-01	14.9059514603761
2014-10-01	15.2254321007524
2015-01-01	15.2010044758516
2015-04-01	14.9470383339915
2015-07-01	14.7988936478747
2015-10-01	14.7656806353982
2016-01-01	14.9392589781445
2016-04-01	14.2894110954134
2016-07-01	14.2448481751187
2016-10-01	14.3178679740256
2017-01-01	14.8585678415043
2017-04-01	14.2200317029071
2017-07-01	14.1269502058598
2017-10-01	14.2746413223725
2018-01-01	14.3329914694693
2018-04-01	13.4963418771164
2018-07-01	13.6578065413873