Quarter	Millions of US Dollars
1967-04-01	20
1967-07-01	20
1967-10-01	20
1968-01-01	20
1968-04-01	20
1968-07-01	20
1968-10-01	20
1969-01-01	20
1969-04-01	20
1969-07-01	20
1969-10-01	20
1970-01-01	20
1970-04-01	20
1970-07-01	20
1970-10-01	20
1971-01-01	48
1971-04-01	49
1971-07-01	50
1971-10-01	96
1972-01-01	130
1972-04-01	130
1972-07-01	160
1972-10-01	226
1973-01-01	277
1973-04-01	323
1973-07-01	325
1973-10-01	302
1974-01-01	315
1974-04-01	312
1974-07-01	331
1974-10-01	350
1975-01-01	377
1975-04-01	394
1975-07-01	393
1975-10-01	396
1976-01-01	412
1976-04-01	477
1976-07-01	520
1976-10-01	672
1977-01-01	827
1977-04-01	1026
1977-07-01	1062
1977-10-01	1229
1978-01-01	1276
1978-04-01	1500
1978-07-01	1642
1978-10-01	1666
1979-01-01	1827
1979-04-01	1976
1979-07-01	2124
1979-10-01	2139
1980-01-01	2046
1980-04-01	2377
1980-07-01	2401
1980-10-01	2357
1981-01-01	2222
1981-04-01	2205
1981-07-01	2241
1981-10-01	2414
1982-01-01	2524
1982-04-01	2672
1982-07-01	2613
1982-10-01	2794
1983-01-01	2958
1983-04-01	3034
1983-07-01	3154
1983-10-01	3444
1984-01-01	4004
1984-04-01	3614
1984-07-01	3524
1984-10-01	4112
1985-01-01	4616
1985-04-01	5015
1985-07-01	5447
1985-10-01	5470
1986-01-01	5404
1986-04-01	5596
1986-07-01	5801
1986-10-01	5463
1987-01-01	6022
1987-04-01	5684
1987-07-01	6411
1987-10-01	7318
1988-01-01	7452
1988-04-01	6954
1988-07-01	6917
1988-10-01	7460
1989-01-01	7526
1989-04-01	7287
1989-07-01	7626
1989-10-01	7097
1990-01-01	7245
1990-04-01	8133
1990-07-01	9122
1990-10-01	9808
1991-01-01	9531
1991-04-01	9676
1991-07-01	10023
1991-10-01	11570
1992-01-01	12235
1992-04-01	14364
1992-07-01	16774
1992-10-01	16837
1993-01-01	17594
1993-04-01	18669
1993-07-01	18877
1993-10-01	18187
1994-01-01	18091
1994-04-01	18487
1994-07-01	20385
1994-10-01	20030
1995-01-01	26678
1995-04-01	26608
1995-07-01	25261
1995-10-01	24541
1996-01-01	23615
1996-04-01	23086
1996-07-01	25298
1996-10-01	25796
1997-01-01	25913
1997-04-01	26830
1997-07-01	27845
1997-10-01	27806
1998-01-01	28158
1998-04-01	30068
1998-07-01	33403
1998-10-01	35378
1999-01-01	34360
1999-04-01	37257
1999-07-01	40992
1999-10-01	43718
2000-01-01	40943
2000-04-01	43059
2000-07-01	43387
2000-10-01	44944
2001-01-01	43693
2001-04-01	47223
2001-07-01	51144
2001-10-01	53537
2002-01-01	58993
2002-04-01	69199
2002-07-01	71450
2002-10-01	83380
2003-01-01	96302
2003-04-01	116828
2003-07-01	127109
2003-10-01	153425
2004-01-01	161725
2004-04-01	172113
2004-07-01	176507
2004-10-01	210849
2005-01-01	219570
2005-04-01	240453
2005-07-01	247446
2005-10-01	292042
2006-01-01	360920
2006-04-01	427069
2006-07-01	449340
2006-10-01	496246
2007-01-01	555893
2007-04-01	605964
2007-07-01	656615
2007-10-01	683323
2008-01-01	732756
2008-04-01	789626
2008-07-01	749153
2008-10-01	735051
2009-01-01	739547
2009-04-01	803353
2009-07-01	853990
2009-10-01	863957
2010-01-01	817518
2010-04-01	735870
2010-07-01	842811
2010-10-01	825358
2011-01-01	882937
2011-04-01	889395
2011-07-01	836796
2011-10-01	803840
2012-01-01	866263
2012-04-01	781701
2012-07-01	778457
2012-10-01	806865
2013-01-01	776324
2013-04-01	780748
2013-07-01	779864
2013-10-01	796483
2014-01-01	770717
2014-04-01	767274
2014-07-01	695463
2014-10-01	656833
2015-01-01	582866
2015-04-01	591413
2015-07-01	584195
2015-10-01	564865
2016-01-01	560865
2016-04-01	543494
2016-07-01	541076
2016-10-01	498768
2017-01-01	488310
2017-04-01	526282
2017-07-01	536833
2017-10-01	544671
2018-01-01	561901
2018-04-01	524702