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	32
1985-01-01	32
1985-04-01	32
1985-07-01	35
1985-10-01	0
1986-01-01	0
1986-04-01	27
1986-07-01	27
1986-10-01	27
1987-01-01	447
1987-04-01	464
1987-07-01	464
1987-10-01	477
1988-01-01	162
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	816
1990-10-01	288
1991-01-01	204
1991-04-01	81
1991-07-01	51
1991-10-01	52
1992-01-01	24
1992-04-01	360
1992-07-01	713
1992-10-01	1271
1993-01-01	1471
1993-04-01	1323
1993-07-01	1436
1993-10-01	1152
1994-01-01	1419
1994-04-01	1419
1994-07-01	1424
1994-10-01	1957
1995-01-01	2177
1995-04-01	3807
1995-07-01	4244
1995-10-01	4561
1996-01-01	4081
1996-04-01	4227
1996-07-01	4044
1996-10-01	6922
1997-01-01	7003
1997-04-01	7189
1997-07-01	7139
1997-10-01	6315
1998-01-01	6555
1998-04-01	8508
1998-07-01	9307
1998-10-01	10181
1999-01-01	9983
1999-04-01	9380
1999-07-01	9318
1999-10-01	9445
2000-01-01	9611
2000-04-01	9180
2000-07-01	10439
2000-10-01	9746
2001-01-01	11159
2001-04-01	11201
2001-07-01	10233
2001-10-01	11672
2002-01-01	8709
2002-04-01	9653
2002-07-01	8289
2002-10-01	7570
2003-01-01	7163
2003-04-01	7934
2003-07-01	9362
2003-10-01	10046
2004-01-01	10913
2004-04-01	9514
2004-07-01	10442
2004-10-01	10284
2005-01-01	11809
2005-04-01	11541
2005-07-01	10639
2005-10-01	11463
2006-01-01	13071
2006-04-01	13532
2006-07-01	15258
2006-10-01	18230
2007-01-01	17956
2007-04-01	22813
2007-07-01	25776
2007-10-01	25041
2008-01-01	27728
2008-04-01	26307
2008-07-01	23383
2008-10-01	18546
2009-01-01	18883
2009-04-01	22791
2009-07-01	25067
2009-10-01	25277
2010-01-01	24029
2010-04-01	23409
2010-07-01	23927
2010-10-01	22717
2011-01-01	26959
2011-04-01	30404
2011-07-01	30149
2011-10-01	35688
2012-01-01	33126
2012-04-01	31353
2012-07-01	35780
2012-10-01	26916
2013-01-01	30698
2013-04-01	34802
2013-07-01	40517
2013-10-01	41807
2014-01-01	43377
2014-04-01	37768
2014-07-01	36569
2014-10-01	46130
2015-01-01	46258
2015-04-01	47016
2015-07-01	45173
2015-10-01	42505
2016-01-01	45722
2016-04-01	49446
2016-07-01	50024
2016-10-01	43013
2017-01-01	39317
2017-04-01	33243
2017-07-01	32297
2017-10-01	37373
2018-01-01	37801
2018-04-01	39989