Quarter	Millions of US Dollars
1966-07-01	15
1966-10-01	15
1967-01-01	30
1967-04-01	30
1967-07-01	30
1967-10-01	30
1968-01-01	30
1968-04-01	30
1968-07-01	30
1968-10-01	30
1969-01-01	30
1969-04-01	30
1969-07-01	30
1969-10-01	30
1970-01-01	30
1970-04-01	30
1970-07-01	30
1970-10-01	30
1971-01-01	30
1971-04-01	31
1971-07-01	32
1971-10-01	32
1972-01-01	32
1972-04-01	66
1972-07-01	86
1972-10-01	142
1973-01-01	198
1973-04-01	275
1973-07-01	304
1973-10-01	340
1974-01-01	416
1974-04-01	464
1974-07-01	620
1974-10-01	1062
1975-01-01	1469
1975-04-01	1724
1975-07-01	1691
1975-10-01	1777
1976-01-01	1901
1976-04-01	2014
1976-07-01	2191
1976-10-01	2543
1977-01-01	2804
1977-04-01	3197
1977-07-01	3669
1977-10-01	4368
1978-01-01	4863
1978-04-01	5195
1978-07-01	6194
1978-10-01	6513
1979-01-01	6606
1979-04-01	6954
1979-07-01	7663
1979-10-01	7637
1980-01-01	7010
1980-04-01	8187
1980-07-01	8478
1980-10-01	8246
1981-01-01	8008
1981-04-01	7723
1981-07-01	8124
1981-10-01	9055
1982-01-01	8951
1982-04-01	8777
1982-07-01	8764
1982-10-01	9412
1983-01-01	9440
1983-04-01	9628
1983-07-01	9710
1983-10-01	9554
1984-01-01	10321
1984-04-01	10187
1984-07-01	10036
1984-10-01	10020
1985-01-01	10276
1985-04-01	10762
1985-07-01	12223
1985-10-01	12632
1986-01-01	14003
1986-04-01	15671
1986-07-01	17135
1986-10-01	17562
1987-01-01	20556
1987-04-01	20841
1987-07-01	20913
1987-10-01	24378
1988-01-01	25807
1988-04-01	24915
1988-07-01	25100
1988-10-01	26765
1989-01-01	27129
1989-04-01	26575
1989-07-01	27579
1989-10-01	29009
1990-01-01	30192
1990-04-01	31916
1990-07-01	34144
1990-10-01	34776
1991-01-01	33846
1991-04-01	32681
1991-07-01	34722
1991-10-01	37563
1992-01-01	36530
1992-04-01	39840
1992-07-01	42659
1992-10-01	38639
1993-01-01	39825
1993-04-01	40897
1993-07-01	42530
1993-10-01	42263
1994-01-01	45636
1994-04-01	47807
1994-07-01	49315
1994-10-01	50908
1995-01-01	59992
1995-04-01	60653
1995-07-01	59063
1995-10-01	60084
1996-01-01	62507
1996-04-01	62143
1996-07-01	62201
1996-10-01	61163
1997-01-01	60611
1997-04-01	61191
1997-07-01	62263
1997-10-01	61323
1998-01-01	62224
1998-04-01	64338
1998-07-01	68680
1998-10-01	72682
1999-01-01	73064
1999-04-01	75268
1999-07-01	78816
1999-10-01	77408
2000-01-01	82063
2000-04-01	86072
2000-07-01	86728
2000-10-01	87512
2001-01-01	92988
2001-04-01	90624
2001-07-01	96337
2001-10-01	101065
2002-01-01	109733
2002-04-01	126283
2002-07-01	124715
2002-10-01	130087
2003-01-01	140489
2003-04-01	153381
2003-07-01	159598
2003-10-01	172176
2004-01-01	180631
2004-04-01	184851
2004-07-01	191112
2004-10-01	206487
2005-01-01	214318
2005-04-01	215431
2005-07-01	212565
2005-10-01	213509
2006-01-01	230487
2006-04-01	254342
2006-07-01	253687
2006-10-01	270126
2007-01-01	305649
2007-04-01	321683
2007-07-01	345356
2007-10-01	344845
2008-01-01	385220
2008-04-01	382535
2008-07-01	354195
2008-10-01	362088
2009-01-01	358679
2009-04-01	378785
2009-07-01	394189
2009-10-01	381760
2010-01-01	365042
2010-04-01	335048
2010-07-01	366313
2010-10-01	356057
2011-01-01	385938
2011-04-01	385269
2011-07-01	365648
2011-10-01	342981
2012-01-01	341525
2012-04-01	321397
2012-07-01	327640
2012-10-01	332818
2013-01-01	319778
2013-04-01	327471
2013-07-01	341733
2013-10-01	345294
2014-01-01	328902
2014-04-01	329558
2014-07-01	300107
2014-10-01	292713
2015-01-01	264819
2015-04-01	273664
2015-07-01	270194
2015-10-01	259222
2016-01-01	273239
2016-04-01	261240
2016-07-01	255558
2016-10-01	245143
2017-01-01	249756
2017-04-01	264915
2017-07-01	273901
2017-10-01	273326
2018-01-01	286606
2018-04-01	271618