Quarter	Percent
1978-04-01	51.6438542341462
1978-07-01	51.6992096991575
1978-10-01	51.8260512806704
1979-01-01	50.6080848982322
1979-04-01	51.6105409871165
1979-07-01	51.9453444997996
1979-10-01	53.0580022198354
1980-01-01	52.0369843209320
1980-04-01	52.9898763726387
1980-07-01	53.5743455679698
1980-10-01	53.2870105448533
1981-01-01	52.2892192274078
1981-04-01	53.8041276143074
1981-07-01	54.0541683179162
1981-10-01	54.3870421801118
1982-01-01	53.1701196859569
1982-04-01	53.9814388312516
1982-07-01	54.3562891180445
1982-10-01	54.4929014049383
1983-01-01	53.1834813152351
1983-04-01	53.9442009002696
1983-07-01	54.1753334442612
1983-10-01	54.2661386589631
1984-01-01	53.5450585348712
1984-04-01	55.5556294342260
1984-07-01	55.7089963934399
1984-10-01	56.3859210901529
1985-01-01	55.8417572914196
1985-04-01	56.9215106072871
1985-07-01	57.5501292005144
1985-10-01	58.7048447288653
1986-01-01	58.5268964526647
1986-04-01	60.7549053654863
1986-07-01	61.0859922833378
1986-10-01	61.3170247714962
1987-01-01	60.3079954885501
1987-04-01	61.9216128155286
1987-07-01	61.8860473754043
1987-10-01	62.1081874608132
1988-01-01	62.0896887633989
1988-04-01	63.7892402782248
1988-07-01	63.5399057298460
1988-10-01	63.9165123908903
1989-01-01	63.2352988952028
1989-04-01	65.3690658130090
1989-07-01	65.7967982146510
1989-10-01	66.4981356167678
1990-01-01	65.8380304423811
1990-04-01	67.4267514956223
1990-07-01	67.0257597715585
1990-10-01	66.8447208035095
1991-01-01	66.2515509441042
1991-04-01	67.8414811918187
1991-07-01	67.3527641351631
1991-10-01	66.7839055288125
1992-01-01	66.7870144649077
1992-04-01	67.4451459650569
1992-07-01	67.5797222756378
1992-10-01	67.3208982993458
1993-01-01	66.3972834467495
1993-04-01	66.8227176302458
1993-07-01	67.2998517137418
1993-10-01	68.0134348354849
1994-01-01	66.7772200175538
1994-04-01	67.5560341806252
1994-07-01	68.3483062338795
1994-10-01	68.2712050945858
1995-01-01	67.7663532986112
1995-04-01	69.0758548061604
1995-07-01	69.5024574474108
1995-10-01	69.6935269011236
1996-01-01	68.5695107240311
1996-04-01	68.8533009371370
1996-07-01	69.3408046446866
1996-10-01	69.3556639768514
1997-01-01	68.9314320349421
1997-04-01	69.4292611348119
1997-07-01	69.5452866568297
1997-10-01	69.3617811919109
1998-01-01	68.3915290148891
1998-04-01	69.4248573498805
1998-07-01	69.8486931443479
1998-10-01	69.5978547746315
1999-01-01	68.4760604022424
1999-04-01	69.2983177593162
1999-07-01	69.6887875044257
1999-10-01	70.0505574978234
2000-01-01	69.3474703608445
2000-04-01	70.6759286912788
2000-07-01	71.2983045360400
2000-10-01	70.5184330449199
2001-01-01	70.0544446930019
2001-04-01	71.6800970453049
2001-07-01	71.4868264861642
2001-10-01	71.2472759422708
2002-01-01	70.7609149593269
2002-04-01	71.2384538787264
2002-07-01	71.9966776648261
2002-10-01	72.2525696318221
2003-01-01	72.4964522251699
2003-04-01	72.9041670513483
2003-07-01	72.5504731984341
2003-10-01	72.0155652547606
2004-01-01	71.2074700517902
2004-04-01	71.7969937922953
2004-07-01	72.0179354388177
2004-10-01	72.4114112171289
2005-01-01	72.8506526968714
2005-04-01	73.9537938027678
2005-07-01	73.9876949885038
2005-10-01	73.9128219986528
2006-01-01	73.4032853892909
2006-04-01	74.4476521647940
2006-07-01	74.5295741497909
2006-10-01	74.4660867534816
2007-01-01	74.2043121092491
2007-04-01	74.6480622259430
2007-07-01	75.0254829215235
2007-10-01	75.2611352608823
2008-01-01	74.8141776081456
2008-04-01	75.5228167030316
2008-07-01	75.5004456368691
2008-10-01	75.6760573343646
2009-01-01	75.7274949362376
2009-04-01	76.0497587035827
2009-07-01	75.5621711509813
2009-10-01	74.8585453887066
2010-01-01	74.3014129382461
2010-04-01	75.0490461167025
2010-07-01	75.5443286242296
2010-10-01	75.6849021752213
2011-01-01	75.1277422670605
2011-04-01	75.7814116753610
2011-07-01	75.8754358798385
2011-10-01	75.7571084487832
2012-01-01	75.0649456093524
2012-04-01	75.6573916443977
2012-07-01	75.8182647945403
2012-10-01	75.7202036958586
2013-01-01	75.5759195906171
2013-04-01	76.1249210664471
2013-07-01	75.7695410090505
2013-10-01	75.7392421175482
2014-01-01	75.6986324140842
2014-04-01	75.9832889520356
2014-07-01	75.9335078152793
2014-10-01	75.8641946833463
2015-01-01	76.0535415972611
2015-04-01	76.6639386149790
2015-07-01	76.6513378503029
2015-10-01	76.9372563864476
2016-01-01	76.7009016841048
2016-04-01	77.0650112713180
2016-07-01	76.7686301626666
2016-10-01	76.9645164407936
2017-01-01	76.7801744861891
2017-04-01	77.7465456770286
2017-07-01	77.6400117622987
2017-10-01	78.5785198096119
2018-01-01	78.5383902051586
2018-04-01	78.8694459654388
2018-07-01	78.3546437256922