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	20
1977-01-01	60
1977-04-01	60
1977-07-01	60
1977-10-01	40
1978-01-01	0
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	0
1979-04-01	0
1979-07-01	0
1979-10-01	0
1980-01-01	14
1980-04-01	59
1980-07-01	83
1980-10-01	149
1981-01-01	147
1981-04-01	224
1981-07-01	203
1981-10-01	185
1982-01-01	265
1982-04-01	142
1982-07-01	141
1982-10-01	182
1983-01-01	113
1983-04-01	244
1983-07-01	289
1983-10-01	338
1984-01-01	382
1984-04-01	259
1984-07-01	226
1984-10-01	443
1985-01-01	699
1985-04-01	648
1985-07-01	1205
1985-10-01	2209
1986-01-01	2240
1986-04-01	2800
1986-07-01	2361
1986-10-01	1289
1987-01-01	1213
1987-04-01	878
1987-07-01	991
1987-10-01	1017
1988-01-01	809
1988-04-01	1340
1988-07-01	1418
1988-10-01	1558
1989-01-01	1521
1989-04-01	650
1989-07-01	659
1989-10-01	1280
1990-01-01	1499
1990-04-01	1535
1990-07-01	1466
1990-10-01	825
1991-01-01	518
1991-04-01	1006
1991-07-01	1133
1991-10-01	1551
1992-01-01	1609
1992-04-01	1981
1992-07-01	2799
1992-10-01	2617
1993-01-01	2958
1993-04-01	3456
1993-07-01	10442
1993-10-01	11508
1994-01-01	10614
1994-04-01	10038
1994-07-01	10258
1994-10-01	9556
1995-01-01	11758
1995-04-01	12669
1995-07-01	13680
1995-10-01	15548
1996-01-01	18497
1996-04-01	19458
1996-07-01	16087
1996-10-01	22069
1997-01-01	18317
1997-04-01	17677
1997-07-01	19661
1997-10-01	21087
1998-01-01	22818
1998-04-01	23911
1998-07-01	28536
1998-10-01	27871
1999-01-01	28406
1999-04-01	31939
1999-07-01	32184
1999-10-01	36280
2000-01-01	38300
2000-04-01	44245
2000-07-01	39255
2000-10-01	39713
2001-01-01	46256
2001-04-01	41719
2001-07-01	43789
2001-10-01	48288
2002-01-01	47956
2002-04-01	54429
2002-07-01	55446
2002-10-01	55329
2003-01-01	62091
2003-04-01	66372
2003-07-01	68124
2003-10-01	78114
2004-01-01	68299
2004-04-01	65632
2004-07-01	62824
2004-10-01	67521
2005-01-01	62877
2005-04-01	63278
2005-07-01	60751
2005-10-01	74438
2006-01-01	76426
2006-04-01	72596
2006-07-01	81558
2006-10-01	76952
2007-01-01	92329
2007-04-01	104192
2007-07-01	133138
2007-10-01	144594
2008-01-01	175717
2008-04-01	190414
2008-07-01	174333
2008-10-01	165216
2009-01-01	189567
2009-04-01	216719
2009-07-01	224011
2009-10-01	209278
2010-01-01	196558
2010-04-01	165779
2010-07-01	172211
2010-10-01	155952
2011-01-01	157424
2011-04-01	164199
2011-07-01	160312
2011-10-01	147738
2012-01-01	169128
2012-04-01	151893
2012-07-01	156216
2012-10-01	148655
2013-01-01	161627
2013-04-01	144292
2013-07-01	136130
2013-10-01	155893
2014-01-01	145648
2014-04-01	149805
2014-07-01	140876
2014-10-01	125799
2015-01-01	137706
2015-04-01	138169
2015-07-01	129918
2015-10-01	129421
2016-01-01	140084
2016-04-01	137763
2016-07-01	158820
2016-10-01	133342
2017-01-01	117717
2017-04-01	120250
2017-07-01	109990
2017-10-01	106845
2018-01-01	102161
2018-04-01	90665