Quarter	Millions of US Dollars
1971-01-01	30
1971-04-01	30
1971-07-01	30
1971-10-01	30
1972-01-01	30
1972-04-01	65
1972-07-01	65
1972-10-01	65
1973-01-01	65
1973-04-01	65
1973-07-01	65
1973-10-01	65
1974-01-01	65
1974-04-01	89
1974-07-01	128
1974-10-01	151
1975-01-01	168
1975-04-01	402
1975-07-01	402
1975-10-01	406
1976-01-01	517
1976-04-01	515
1976-07-01	621
1976-10-01	721
1977-01-01	716
1977-04-01	842
1977-07-01	956
1977-10-01	1000
1978-01-01	1075
1978-04-01	1074
1978-07-01	1166
1978-10-01	1244
1979-01-01	1326
1979-04-01	1334
1979-07-01	1463
1979-10-01	1426
1980-01-01	1347
1980-04-01	1382
1980-07-01	1385
1980-10-01	1363
1981-01-01	1232
1981-04-01	1208
1981-07-01	1240
1981-10-01	1292
1982-01-01	1268
1982-04-01	1376
1982-07-01	1352
1982-10-01	2074
1983-01-01	2262
1983-04-01	2730
1983-07-01	2777
1983-10-01	2926
1984-01-01	2984
1984-04-01	3055
1984-07-01	3311
1984-10-01	3671
1985-01-01	3781
1985-04-01	3909
1985-07-01	4297
1985-10-01	4262
1986-01-01	4846
1986-04-01	5232
1986-07-01	5853
1986-10-01	6041
1987-01-01	6586
1987-04-01	7101
1987-07-01	7188
1987-10-01	7669
1988-01-01	7375
1988-04-01	7455
1988-07-01	7560
1988-10-01	8426
1989-01-01	8572
1989-04-01	8181
1989-07-01	8142
1989-10-01	8458
1990-01-01	8806
1990-04-01	8643
1990-07-01	9291
1990-10-01	9409
1991-01-01	9406
1991-04-01	10796
1991-07-01	12189
1991-10-01	12897
1992-01-01	13056
1992-04-01	13529
1992-07-01	13973
1992-10-01	14167
1993-01-01	14507
1993-04-01	15801
1993-07-01	18923
1993-10-01	18798
1994-01-01	20877
1994-04-01	21180
1994-07-01	22560
1994-10-01	24115
1995-01-01	26646
1995-04-01	28511
1995-07-01	30631
1995-10-01	31175
1996-01-01	33188
1996-04-01	36961
1996-07-01	38054
1996-10-01	37948
1997-01-01	40982
1997-04-01	47048
1997-07-01	52045
1997-10-01	56308
1998-01-01	58340
1998-04-01	65001
1998-07-01	70229
1998-10-01	70059
1999-01-01	70676
1999-04-01	70830
1999-07-01	77121
1999-10-01	74539
2000-01-01	73291
2000-04-01	80218
2000-07-01	78585
2000-10-01	92320
2001-01-01	90423
2001-04-01	93292
2001-07-01	95413
2001-10-01	96397
2002-01-01	96482
2002-04-01	111920
2002-07-01	110653
2002-10-01	116230
2003-01-01	119833
2003-04-01	120323
2003-07-01	129030
2003-10-01	146581
2004-01-01	176075
2004-04-01	184582
2004-07-01	204361
2004-10-01	237616
2005-01-01	239659
2005-04-01	232769
2005-07-01	256270
2005-10-01	253163
2006-01-01	266993
2006-04-01	284055
2006-07-01	294349
2006-10-01	298106
2007-01-01	322807
2007-04-01	340764
2007-07-01	373001
2007-10-01	360695
2008-01-01	392395
2008-04-01	428108
2008-07-01	396161
2008-10-01	352433
2009-01-01	365523
2009-04-01	398402
2009-07-01	408277
2009-10-01	393909
2010-01-01	390258
2010-04-01	365120
2010-07-01	397216
2010-10-01	380346
2011-01-01	397509
2011-04-01	398865
2011-07-01	382637
2011-10-01	369225
2012-01-01	388026
2012-04-01	369065
2012-07-01	377999
2012-10-01	390068
2013-01-01	367202
2013-04-01	361107
2013-07-01	355690
2013-10-01	360540
2014-01-01	366907
2014-04-01	389974
2014-07-01	392972
2014-10-01	384402
2015-01-01	372790
2015-04-01	405397
2015-07-01	410547
2015-10-01	401037
2016-01-01	407662
2016-04-01	428452
2016-07-01	430506
2016-10-01	416097
2017-01-01	407812
2017-04-01	415989
2017-07-01	424383
2017-10-01	430922
2018-01-01	448449
2018-04-01	436469