Quarter	Millions of US Dollars
1971-01-01	25
1971-07-01	24
1971-10-01	31
1972-01-01	74
1972-04-01	70
1972-07-01	41
1972-10-01	142
1973-04-01	136
1973-07-01	54
1973-10-01	344
1974-01-01	94
1974-04-01	363
1974-07-01	30
1974-10-01	72
1975-01-01	64
1975-04-01	70
1975-07-01	46
1975-10-01	25
1976-01-01	61
1976-04-01	56
1976-07-01	47
1976-10-01	78
1977-01-01	159
1977-04-01	52
1977-07-01	43
1977-10-01	68
1978-01-01	125
1978-04-01	127
1978-07-01	62
1978-10-01	100
1979-04-01	59
1979-07-01	28
1979-10-01	-25
1980-04-01	53
1980-07-01	-11
1980-10-01	-25
1981-01-01	-36
1982-01-01	-64
1982-04-01	-5
1982-07-01	40
1983-04-01	24
1983-07-01	38
1983-10-01	6
1984-01-01	110
1984-04-01	83
1984-07-01	83
1984-10-01	79
1985-01-01	38
1985-04-01	-60
1985-07-01	10
1985-10-01	-467
1986-01-01	-98
1986-04-01	-63
1986-07-01	-34
1986-10-01	-110
1987-01-01	-119
1987-04-01	-125
1987-07-01	-172
1987-10-01	-117
1988-01-01	-61
1988-04-01	-91
1988-07-01	-37
1988-10-01	76
1989-01-01	-147
1989-04-01	-133
1989-07-01	-64
1989-10-01	-68
1990-01-01	-64
1990-04-01	-196
1990-07-01	-89
1990-10-01	-110
1991-01-01	-119
1991-04-01	864
1991-10-01	114
1992-01-01	2319
1992-10-01	-161
1993-04-01	-34
1993-07-01	92
1993-10-01	708
1994-01-01	552
1994-04-01	-332
1994-07-01	54
1994-10-01	575
1995-01-01	-3
1995-04-01	283
1995-07-01	3
1995-10-01	203
1996-01-01	154
1996-04-01	3
1996-07-01	293
1996-10-01	522
1997-01-01	-67
1997-04-01	807
1997-07-01	176
1997-10-01	-80
1998-01-01	1336
1998-04-01	-36
1998-07-01	2
1998-10-01	70
1999-01-01	-60
1999-04-01	2818
1999-07-01	-27
1999-10-01	-375
2000-01-01	1270
2000-04-01	1088
2000-07-01	-9
2000-10-01	-7
2001-01-01	33
2001-04-01	612
2001-07-01	1881
2001-10-01	-40
2002-01-01	373
2002-04-01	998
2002-07-01	-227
2002-10-01	-603
2003-01-01	-2
2003-04-01	2158
2003-07-01	461
2003-10-01	-760
2004-01-01	494
2004-04-01	1464
2004-07-01	-6
2004-10-01	476
2005-01-01	-6
2005-04-01	-5
2005-07-01	1244
2005-10-01	687
2006-01-01	2518
2006-04-01	-456
2006-07-01	-506
2006-10-01	-219
2007-01-01	-279
2007-04-01	1584
2007-07-01	1370
2007-10-01	1280
2008-01-01	-9
2008-04-01	989
2008-07-01	-609
2009-01-01	971
2009-04-01	8000
2009-07-01	491
2009-10-01	7159
2010-01-01	3534
2010-04-01	3731
2010-07-01	-13
2010-10-01	3532
2011-01-01	1361
2011-04-01	1000
2011-07-01	-613
2011-10-01	5470
2012-01-01	1863
2012-04-01	-1200
2012-07-01	3344
2012-10-01	1500
2013-01-01	2583
2013-04-01	-1053
2013-07-01	4983
2013-10-01	3911
2014-01-01	1537
2014-04-01	-688
2014-07-01	5413
2014-10-01	-1153
2015-01-01	-603
2015-04-01	3084
2015-07-01	1232
2015-10-01	5365
2016-01-01	1963
2016-04-01	23538
2016-07-01	363
2016-10-01	40768
2017-01-01	16082
2017-04-01	19014
2017-07-01	5064
2017-10-01	25525
2018-01-01	18484
2018-04-01	36677