Quarter	Millions of US Dollars
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	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	0
1978-04-01	0
1978-07-01	26
1978-10-01	26
1979-01-01	25
1979-04-01	25
1979-07-01	0
1979-10-01	0
1980-01-01	0
1980-04-01	0
1980-07-01	0
1980-10-01	41
1981-01-01	66
1981-04-01	66
1981-07-01	66
1981-10-01	25
1982-01-01	0
1982-04-01	15
1982-07-01	15
1982-10-01	15
1983-01-01	15
1983-04-01	0
1983-07-01	0
1983-10-01	37
1984-01-01	39
1984-04-01	36
1984-07-01	33
1984-10-01	38
1985-01-01	38
1985-04-01	38
1985-07-01	40
1985-10-01	0
1986-01-01	25
1986-04-01	52
1986-07-01	52
1986-10-01	52
1987-01-01	447
1987-04-01	514
1987-07-01	514
1987-10-01	527
1988-01-01	212
1988-04-01	203
1988-07-01	238
1988-10-01	385
1989-01-01	264
1989-04-01	500
1989-07-01	772
1989-10-01	1171
1990-01-01	1241
1990-04-01	1040
1990-07-01	786
1990-10-01	258
1991-01-01	149
1991-04-01	26
1991-07-01	76
1991-10-01	77
1992-01-01	74
1992-04-01	410
1992-07-01	713
1992-10-01	1271
1993-01-01	1471
1993-04-01	1323
1993-07-01	1273
1993-10-01	945
1994-01-01	1149
1994-04-01	1060
1994-07-01	1111
1994-10-01	1633
1995-01-01	1846
1995-04-01	3402
1995-07-01	3875
1995-10-01	4498
1996-01-01	3841
1996-04-01	3940
1996-07-01	3728
1996-10-01	6678
1997-01-01	6536
1997-04-01	6741
1997-07-01	6952
1997-10-01	6187
1998-01-01	6395
1998-04-01	8236
1998-07-01	8956
1998-10-01	9950
1999-01-01	9805
1999-04-01	8993
1999-07-01	8739
1999-10-01	8600
2000-01-01	8831
2000-04-01	7902
2000-07-01	9351
2000-10-01	9032
2001-01-01	10153
2001-04-01	10124
2001-07-01	8825
2001-10-01	10325
2002-01-01	7879
2002-04-01	9209
2002-07-01	7834
2002-10-01	7124
2003-01-01	6897
2003-04-01	6872
2003-07-01	8104
2003-10-01	8066
2004-01-01	8559
2004-04-01	7636
2004-07-01	6885
2004-10-01	7399
2005-01-01	9014
2005-04-01	9014
2005-07-01	9606
2005-10-01	9935
2006-01-01	11509
2006-04-01	11595
2006-07-01	12986
2006-10-01	16302
2007-01-01	16443
2007-04-01	20943
2007-07-01	23445
2007-10-01	21315
2008-01-01	23316
2008-04-01	21943
2008-07-01	20660
2008-10-01	16409
2009-01-01	16628
2009-04-01	20141
2009-07-01	21645
2009-10-01	22454
2010-01-01	21431
2010-04-01	21137
2010-07-01	21852
2010-10-01	21120
2011-01-01	24677
2011-04-01	28531
2011-07-01	28357
2011-10-01	33218
2012-01-01	30897
2012-04-01	29349
2012-07-01	32803
2012-10-01	24375
2013-01-01	28644
2013-04-01	32319
2013-07-01	36842
2013-10-01	38512
2014-01-01	39494
2014-04-01	32971
2014-07-01	31027
2014-10-01	40350
2015-01-01	41759
2015-04-01	43490
2015-07-01	43560
2015-10-01	41686
2016-01-01	43645
2016-04-01	44930
2016-07-01	45317
2016-10-01	38408
2017-01-01	35595
2017-04-01	33322
2017-07-01	31902
2017-10-01	36376
2018-01-01	39201
2018-04-01	39100