Quarter	Millions of US Dollars
1966-01-01	20
1967-10-01	15
1971-01-01	15
1971-07-01	15
1972-01-01	120
1972-04-01	30
1972-07-01	25
1972-10-01	66
1973-01-01	81
1973-04-01	39
1973-10-01	46
1974-01-01	22
1974-04-01	50
1974-10-01	73
1975-01-01	308
1975-04-01	347
1975-07-01	79
1975-10-01	304
1976-01-01	275
1976-04-01	162
1976-07-01	269
1976-10-01	386
1977-01-01	341
1977-04-01	404
1977-07-01	351
1977-10-01	434
1978-01-01	81
1978-04-01	440
1978-07-01	36
1978-10-01	119
1979-01-01	256
1979-04-01	801
1979-07-01	55
1979-10-01	389
1980-01-01	604
1980-04-01	939
1980-07-01	676
1980-10-01	639
1981-01-01	576
1981-04-01	278
1981-07-01	164
1981-10-01	425
1982-01-01	1228
1982-04-01	124
1982-07-01	306
1982-10-01	570
1983-01-01	1843
1983-04-01	-415
1983-07-01	55
1983-10-01	1147
1984-01-01	749
1984-04-01	1956
1984-07-01	1009
1984-10-01	1901
1985-01-01	-1218
1985-04-01	3004
1985-07-01	289
1985-10-01	-1014
1986-01-01	999
1986-04-01	958
1986-07-01	1510
1986-10-01	143
1987-01-01	1649
1987-04-01	273
1987-07-01	-4
1987-10-01	-274
1988-01-01	1602
1988-04-01	479
1988-07-01	733
1988-10-01	1194
1989-01-01	2782
1989-04-01	930
1989-07-01	1126
1989-10-01	3045
1990-01-01	1495
1990-04-01	-109
1990-07-01	981
1990-10-01	128
1991-01-01	83
1991-04-01	1709
1991-07-01	148
1991-10-01	-1700
1992-01-01	-1078
1992-04-01	1871
1992-07-01	1346
1992-10-01	733
1993-01-01	3173
1993-04-01	-1027
1993-07-01	8723
1993-10-01	3653
1994-01-01	4811
1994-04-01	6621
1994-07-01	4053
1994-10-01	1602
1995-01-01	-1558
1995-04-01	1111
1995-07-01	4548
1995-10-01	-584
1996-01-01	2409
1996-04-01	5112
1996-07-01	-866
1996-10-01	581
1997-01-01	300
1997-04-01	457
1997-07-01	1124
1997-10-01	-2470
1998-01-01	-4482
1998-04-01	4692
1998-07-01	-1827
1998-10-01	-4702
1999-01-01	-4609
1999-04-01	4119
1999-07-01	3378
1999-10-01	-177
2000-01-01	4197
2000-04-01	339
2000-07-01	-1423
2000-10-01	3314
2001-01-01	1
2001-04-01	2842
2001-07-01	-2723
2001-10-01	2625
2002-01-01	-76
2002-04-01	3926
2002-07-01	1175
2002-10-01	-683
2003-01-01	2160
2003-04-01	335
2003-07-01	1214
2003-10-01	4801
2004-01-01	8277
2004-04-01	353
2004-07-01	2393
2004-10-01	3837
2005-01-01	4209
2005-04-01	15708
2005-07-01	4374
2005-10-01	-1078
2006-01-01	11946
2006-04-01	-314
2006-07-01	-803
2006-10-01	8193
2007-01-01	14467
2007-04-01	22469
2007-07-01	-2089
2007-10-01	9389
2008-01-01	-1508
2008-04-01	25154
2008-07-01	19595
2008-10-01	-12302
2009-01-01	25433
2009-04-01	30146
2009-07-01	20670
2009-10-01	8033
2010-01-01	28200
2010-04-01	-11278
2010-07-01	-2156
2010-10-01	8698
2011-01-01	6579
2011-04-01	20806
2011-07-01	15854
2011-10-01	-1406
2012-01-01	17311
2012-04-01	16273
2012-07-01	7430
2012-10-01	12277
2013-01-01	18007
2013-04-01	3481
2013-07-01	15835
2013-10-01	-10874
2014-01-01	1105
2014-04-01	807
2014-07-01	7233
2014-10-01	11401
2015-01-01	60
2015-04-01	-5
2015-07-01	8545
2015-10-01	10255
2016-01-01	-2189
2016-04-01	-7519
2016-07-01	-95
2016-10-01	4987
2017-01-01	15607
2017-04-01	3373
2017-07-01	-1417
2017-10-01	-5558
2018-01-01	6290
2018-04-01	6689