Quarter	Billions of US Dollars
1966-01-01	15
1966-04-01	20
1971-01-01	12
1971-04-01	15
1972-04-01	58
1972-07-01	16
1973-01-01	31
1973-04-01	20
1973-07-01	16
1974-04-01	50
1975-01-01	24
1975-04-01	17
1975-07-01	48
1976-01-01	108
1976-10-01	83
1977-01-01	146
1977-04-01	548
1977-07-01	33
1978-01-01	117
1978-04-01	31
1978-07-01	287
1979-04-01	99
1979-07-01	105
1980-01-01	37
1980-04-01	112
1980-07-01	13
1980-10-01	56
1981-01-01	-88
1981-04-01	69
1981-07-01	-1
1981-10-01	-25
1982-01-01	182
1982-04-01	-155
1982-07-01	1
1982-10-01	26
1983-01-01	-102
1983-04-01	367
1983-07-01	-64
1983-10-01	258
1984-01-01	-116
1984-04-01	-45
1984-07-01	-68
1984-10-01	38
1985-01-01	2
1985-04-01	-30
1985-07-01	62
1985-10-01	23
1986-01-01	-21
1986-04-01	702
1986-07-01	57
1986-10-01	13
1987-01-01	326
1987-04-01	66
1987-07-01	449
1987-10-01	88
1988-01-01	980
1988-04-01	216
1988-07-01	888
1988-10-01	493
1989-01-01	971
1989-04-01	506
1989-07-01	330
1989-10-01	687
1990-01-01	341
1990-04-01	233
1990-07-01	769
1990-10-01	662
1991-01-01	290
1991-04-01	1467
1991-07-01	360
1991-10-01	226
1992-01-01	1170
1992-04-01	462
1992-07-01	-39
1992-10-01	372
1993-01-01	-360
1993-04-01	76
1993-07-01	1824
1993-10-01	935
1994-01-01	391
1994-04-01	1012
1994-07-01	411
1994-10-01	1037
1995-01-01	925
1995-04-01	2088
1995-07-01	2693
1995-10-01	562
1996-01-01	1513
1996-04-01	3734
1996-07-01	2224
1996-10-01	3048
1997-01-01	1056
1997-04-01	1715
1997-07-01	1056
1997-10-01	908
1998-01-01	4284
1998-04-01	3185
1998-07-01	-3254
1998-10-01	2265
1999-01-01	1446
1999-04-01	3008
1999-07-01	6361
1999-10-01	2765
2000-01-01	-417
2000-04-01	4858
2000-07-01	3437
2000-10-01	7620
2001-01-01	12499
2001-04-01	9413
2001-07-01	5786
2001-10-01	9144
2002-01-01	5584
2002-04-01	8635
2002-07-01	-7938
2002-10-01	2088
2003-01-01	2190
2003-04-01	3810
2003-07-01	7214
2003-10-01	26625
2004-01-01	2112
2004-04-01	9666
2004-07-01	207
2004-10-01	13030
2005-01-01	14201
2005-04-01	19908
2005-07-01	21854
2005-10-01	19889
2006-01-01	11701
2006-04-01	16125
2006-07-01	21044
2006-10-01	23595
2007-01-01	9817
2007-04-01	16469
2007-07-01	15950
2007-10-01	13567
2008-01-01	-3272
2008-04-01	28059
2008-07-01	-3264
2008-10-01	-11616
2009-01-01	-5378
2009-04-01	10414
2009-07-01	18402
2009-10-01	8039
2010-01-01	4412
2010-04-01	-7802
2010-07-01	-5270
2010-10-01	-943
2011-01-01	3596
2011-04-01	4490
2011-07-01	-2197
2011-10-01	-2684
2012-01-01	23429
2012-04-01	4367
2012-07-01	5742
2012-10-01	13240
2013-01-01	17201
2013-04-01	20874
2013-07-01	6425
2013-10-01	11229
2014-01-01	13008
2014-04-01	10783
2014-07-01	1299
2014-10-01	-1897
2015-01-01	31817
2015-04-01	8939
2015-07-01	22384
2015-10-01	20926
2016-01-01	9553
2016-04-01	16425
2016-07-01	14808
2016-10-01	16638
2017-01-01	9203
2017-04-01	21047
2017-07-01	28276
2017-10-01	25544
2018-01-01	13882
2018-04-01	1548