Quarter	Millions of US Dollars
1967-04-01	0
1967-07-01	0
1967-10-01	0
1968-01-01	0
1968-04-01	0
1968-07-01	0
1968-10-01	0
1969-01-01	0
1969-04-01	0
1969-07-01	0
1969-10-01	0
1970-01-01	0
1970-04-01	0
1970-07-01	0
1970-10-01	0
1971-01-01	0
1971-04-01	0
1971-07-01	0
1971-10-01	0
1972-01-01	0
1972-04-01	0
1972-07-01	0
1972-10-01	0
1973-01-01	0
1973-04-01	0
1973-07-01	0
1973-10-01	0
1974-01-01	0
1974-04-01	0
1974-07-01	0
1974-10-01	0
1975-01-01	0
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	24
1977-04-01	52
1977-07-01	53
1977-10-01	59
1978-01-01	30
1978-04-01	0
1978-07-01	0
1978-10-01	19
1979-01-01	18
1979-04-01	81
1979-07-01	87
1979-10-01	97
1980-01-01	158
1980-04-01	331
1980-07-01	330
1980-10-01	324
1981-01-01	306
1981-04-01	155
1981-07-01	155
1981-10-01	252
1982-01-01	225
1982-04-01	147
1982-07-01	154
1982-10-01	42
1983-01-01	70
1983-04-01	297
1983-07-01	287
1983-10-01	320
1984-01-01	391
1984-04-01	312
1984-07-01	410
1984-10-01	746
1985-01-01	1550
1985-04-01	1926
1985-07-01	1890
1985-10-01	2077
1986-01-01	1311
1986-04-01	1413
1986-07-01	1656
1986-10-01	1346
1987-01-01	2189
1987-04-01	1701
1987-07-01	2217
1987-10-01	3823
1988-01-01	4312
1988-04-01	5214
1988-07-01	4581
1988-10-01	5466
1989-01-01	4663
1989-04-01	4404
1989-07-01	4902
1989-10-01	5002
1990-01-01	4863
1990-04-01	5217
1990-07-01	5669
1990-10-01	4164
1991-01-01	5444
1991-04-01	5084
1991-07-01	4857
1991-10-01	5254
1992-01-01	4678
1992-04-01	6773
1992-07-01	8713
1992-10-01	8438
1993-01-01	7761
1993-04-01	6792
1993-07-01	10544
1993-10-01	12504
1994-01-01	12050
1994-04-01	13523
1994-07-01	13676
1994-10-01	13474
1995-01-01	13240
1995-04-01	16337
1995-07-01	19206
1995-10-01	22476
1996-01-01	22655
1996-04-01	22228
1996-07-01	18278
1996-10-01	20603
1997-01-01	22831
1997-04-01	20907
1997-07-01	22150
1997-10-01	24347
1998-01-01	28594
1998-04-01	28908
1998-07-01	29379
1998-10-01	32615
1999-01-01	26725
1999-04-01	27339
1999-07-01	31468
1999-10-01	30304
2000-01-01	32092
2000-04-01	44541
2000-07-01	40855
2000-10-01	45591
2001-01-01	43919
2001-04-01	50072
2001-07-01	55683
2001-10-01	62703
2002-01-01	59088
2002-04-01	60337
2002-07-01	65036
2002-10-01	66109
2003-01-01	74308
2003-04-01	76971
2003-07-01	81595
2003-10-01	85868
2004-01-01	89248
2004-04-01	94005
2004-07-01	88223
2004-10-01	98277
2005-01-01	97470
2005-04-01	95315
2005-07-01	92038
2005-10-01	104890
2006-01-01	100077
2006-04-01	102416
2006-07-01	109655
2006-10-01	99822
2007-01-01	107526
2007-04-01	127084
2007-07-01	158378
2007-10-01	179368
2008-01-01	205030
2008-04-01	215189
2008-07-01	181747
2008-10-01	157197
2009-01-01	162865
2009-04-01	164405
2009-07-01	167793
2009-10-01	160657
2010-01-01	161212
2010-04-01	157140
2010-07-01	194978
2010-10-01	163609
2011-01-01	205088
2011-04-01	209207
2011-07-01	194779
2011-10-01	211146
2012-01-01	196909
2012-04-01	162655
2012-07-01	151579
2012-10-01	138797
2013-01-01	135670
2013-04-01	149542
2013-07-01	190497
2013-10-01	176372
2014-01-01	167433
2014-04-01	148814
2014-07-01	118684
2014-10-01	117933
2015-01-01	113477
2015-04-01	121379
2015-07-01	129668
2015-10-01	125854
2016-01-01	118173
2016-04-01	120329
2016-07-01	104848
2016-10-01	104946
2017-01-01	109007
2017-04-01	110299
2017-07-01	114292
2017-10-01	101705
2018-01-01	98521
2018-04-01	90019