Quarter	Millions of US Dollars
1972-01-01	20
1972-04-01	40
1974-07-01	9
1976-10-01	14
1977-04-01	2
1977-07-01	25
1978-01-01	91
1978-07-01	70
1978-10-01	42
1979-01-01	81
1979-07-01	115
1980-04-01	100
1980-07-01	25
1982-01-01	-14
1982-07-01	-25
1983-01-01	-9
1983-04-01	100
1984-01-01	-20
1984-10-01	100
1985-07-01	35
1985-10-01	-102
1986-01-01	-20
1986-10-01	18
1987-01-01	97
1987-04-01	117
1987-07-01	-26
1988-01-01	-92
1988-10-01	-1
1989-04-01	-58
1989-07-01	-71
1990-07-01	-87
1990-10-01	-120
1992-01-01	-103
1992-04-01	-76
1993-01-01	-41
1993-10-01	-89
1994-01-01	-112
1994-10-01	30
1995-07-01	0
1995-10-01	-115
1996-01-01	42
1996-04-01	45
1996-07-01	3285
1996-10-01	-87
1997-01-01	393
1997-04-01	8
1997-07-01	815
1997-10-01	124
1998-01-01	-1
1998-04-01	300
1998-07-01	-75
1998-10-01	-614
1999-01-01	500
1999-04-01	-5
1999-07-01	-1
1999-10-01	-5
2000-04-01	-30
2000-07-01	350
2000-10-01	-5
2001-01-01	1031
2001-04-01	-150
2001-07-01	-43
2001-10-01	-359
2002-01-01	-347
2002-04-01	-5
2002-07-01	96
2002-10-01	24
2003-01-01	168
2003-04-01	-7
2003-07-01	-32
2003-10-01	-5
2004-01-01	187
2004-04-01	-29
2004-07-01	-20
2004-10-01	595
2005-01-01	-8
2005-04-01	-5
2005-07-01	396
2005-10-01	1106
2006-01-01	1303
2006-04-01	-610
2006-07-01	54
2006-10-01	291
2007-04-01	445
2007-10-01	475
2008-04-01	-370
2008-10-01	-5
2009-01-01	323
2009-04-01	-5
2009-10-01	1000
2010-04-01	97
2010-07-01	30
2010-10-01	-138
2011-01-01	57
2011-04-01	244
2011-07-01	819
2011-10-01	277
2012-01-01	-140
2012-04-01	374
2012-07-01	-287
2012-10-01	1058
2013-01-01	317
2013-04-01	1260
2013-07-01	76
2013-10-01	278
2014-01-01	199
2014-04-01	1556
2014-07-01	1251
2014-10-01	-226
2015-01-01	-103
2015-04-01	454
2015-07-01	62
2015-10-01	429
2016-01-01	666
2016-04-01	572
2016-07-01	-20
2016-10-01	385
2017-01-01	211
2017-04-01	1135
2017-07-01	1090
2017-10-01	109
2018-01-01	-68
2018-04-01	1954