Quarter	Millions of US Dollars
1966-01-01	20
1966-04-01	10
1966-07-01	15
1967-01-01	14
1967-04-01	80
1967-10-01	15
1968-01-01	154
1968-04-01	90
1968-07-01	105
1968-10-01	51
1969-01-01	85
1969-04-01	15
1969-07-01	10
1969-10-01	100
1970-10-01	15
1971-01-01	398
1971-04-01	206
1971-07-01	71
1971-10-01	244
1972-01-01	829
1972-04-01	659
1972-07-01	802
1972-10-01	1168
1973-01-01	932
1973-04-01	547
1973-07-01	552
1973-10-01	804
1974-01-01	542
1974-04-01	699
1974-07-01	677
1974-10-01	1029
1975-01-01	2108
1975-04-01	2025
1975-07-01	1701
1975-10-01	2701
1976-01-01	4428
1976-04-01	2893
1976-07-01	2193
1976-10-01	3514
1977-01-01	2004
1977-04-01	2115
1977-07-01	2476
1977-10-01	2680
1978-01-01	2612
1978-04-01	2551
1978-07-01	1705
1978-10-01	1455
1979-01-01	2998
1979-04-01	2520
1979-07-01	2474
1979-10-01	1144
1980-01-01	894
1980-04-01	2424
1980-07-01	986
1980-10-01	2395
1981-01-01	2183
1981-04-01	2408
1981-07-01	3890
1981-10-01	3732
1982-01-01	3733
1982-04-01	2665
1982-07-01	2907
1982-10-01	3345
1983-01-01	4251
1983-04-01	2555
1983-07-01	1291
1983-10-01	2075
1984-01-01	4590
1984-04-01	2727
1984-07-01	3955
1984-10-01	5306
1985-01-01	8714
1985-04-01	5855
1985-07-01	6565
1985-10-01	3610
1986-01-01	9725
1986-04-01	15830
1986-07-01	9541
1986-10-01	7910
1987-01-01	10063
1987-04-01	12994
1987-07-01	12261
1987-10-01	1027
1988-01-01	4558
1988-04-01	10261
1988-07-01	18076
1988-10-01	7370
1989-01-01	15623
1989-04-01	26771
1989-07-01	13515
1989-10-01	16139
1990-01-01	9614
1990-04-01	785
1990-07-01	9226
1990-10-01	13651
1991-01-01	13020
1991-04-01	18342
1991-07-01	16498
1991-10-01	17185
1992-01-01	7600
1992-04-01	8964
1992-07-01	-6139
1992-10-01	8104
1993-01-01	-8741
1993-04-01	-13795
1993-07-01	10680
1993-10-01	5586
1994-01-01	6938
1994-04-01	-1349
1994-07-01	-1163
1994-10-01	-5018
1995-01-01	-8211
1995-04-01	-666
1995-07-01	-5494
1995-10-01	5709
1996-01-01	4512
1996-04-01	6601
1996-07-01	659
1996-10-01	11042
1997-01-01	5990
1997-04-01	12697
1997-07-01	14381
1997-10-01	-4832
1998-01-01	4981
1998-04-01	19426
1998-07-01	4439
1998-10-01	13996
1999-01-01	20634
1999-04-01	39011
1999-07-01	31755
1999-10-01	25596
2000-01-01	12854
2000-04-01	47430
2000-07-01	45040
2000-10-01	38918
2001-01-01	54657
2001-04-01	55844
2001-07-01	12218
2001-10-01	44045
2002-01-01	2269
2002-04-01	29509
2002-07-01	-7299
2002-10-01	159
2003-01-01	6523
2003-04-01	25925
2003-07-01	11441
2003-10-01	30163
2004-01-01	885
2004-04-01	9482
2004-07-01	-1169
2004-10-01	22707
2005-01-01	7268
2005-04-01	6605
2005-07-01	-18691
2005-10-01	30028
2006-01-01	23396
2006-04-01	24060
2006-07-01	25615
2006-10-01	35748
2007-01-01	22587
2007-04-01	70719
2007-07-01	-30
2007-10-01	34475
2008-01-01	4732
2008-04-01	54258
2008-07-01	21403
2008-10-01	4251
2009-01-01	45466
2009-04-01	92684
2009-07-01	45179
2009-10-01	46766
2010-01-01	44999
2010-04-01	26290
2010-07-01	36989
2010-10-01	50760
2011-01-01	45028
2011-04-01	64626
2011-07-01	22158
2011-10-01	40103
2012-01-01	73143
2012-04-01	51766
2012-07-01	84316
2012-10-01	97920
2013-01-01	77647
2013-04-01	79346
2013-07-01	77941
2013-10-01	121861
2014-01-01	33600
2014-04-01	85863
2014-07-01	81023
2014-10-01	72278
2015-01-01	74056
2015-04-01	82019
2015-07-01	21635
2015-10-01	36960
2016-01-01	65468
2016-04-01	73074
2016-07-01	40457
2016-10-01	49433
2017-01-01	66946
2017-04-01	63311
2017-07-01	95987
2017-10-01	45644
2018-01-01	29396
2018-04-01	68064