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	338
1971-04-01	156
1971-07-01	71
1971-10-01	224
1972-01-01	690
1972-04-01	628
1972-07-01	731
1972-10-01	1054
1973-01-01	866
1973-04-01	433
1973-07-01	487
1973-10-01	690
1974-01-01	527
1974-04-01	699
1974-07-01	640
1974-10-01	979
1975-01-01	1953
1975-04-01	1780
1975-07-01	1584
1975-10-01	2584
1976-01-01	4389
1976-04-01	2785
1976-07-01	1818
1976-10-01	3256
1977-01-01	1909
1977-04-01	1937
1977-07-01	1862
1977-10-01	2204
1978-01-01	2211
1978-04-01	2179
1978-07-01	1488
1978-10-01	1208
1979-01-01	2752
1979-04-01	2538
1979-07-01	2218
1979-10-01	1090
1980-01-01	912
1980-04-01	2357
1980-07-01	930
1980-10-01	2371
1981-01-01	2075
1981-04-01	2006
1981-07-01	3438
1981-10-01	3155
1982-01-01	3503
1982-04-01	2444
1982-07-01	3095
1982-10-01	3172
1983-01-01	4105
1983-04-01	2502
1983-07-01	1260
1983-10-01	2216
1984-01-01	4580
1984-04-01	2642
1984-07-01	4017
1984-10-01	5230
1985-01-01	8177
1985-04-01	5422
1985-07-01	6526
1985-10-01	4145
1986-01-01	9766
1986-04-01	15849
1986-07-01	9408
1986-10-01	8134
1987-01-01	10245
1987-04-01	12931
1987-07-01	12299
1987-10-01	1200
1988-01-01	4579
1988-04-01	10622
1988-07-01	18494
1988-10-01	7655
1989-01-01	15706
1989-04-01	26740
1989-07-01	13715
1989-10-01	15874
1990-01-01	8127
1990-04-01	552
1990-07-01	8839
1990-10-01	12872
1991-01-01	12936
1991-04-01	16759
1991-07-01	15837
1991-10-01	15304
1992-01-01	6833
1992-04-01	7722
1992-07-01	-7748
1992-10-01	6242
1993-01-01	-9493
1993-04-01	-16749
1993-07-01	7166
1993-10-01	-2905
1994-01-01	1441
1994-04-01	-4595
1994-07-01	-4034
1994-10-01	-6689
1995-01-01	-5299
1995-04-01	-1305
1995-07-01	-8962
1995-10-01	3365
1996-01-01	1125
1996-04-01	-399
1996-07-01	-2545
1996-10-01	275
1997-01-01	785
1997-04-01	4143
1997-07-01	3086
1997-10-01	-6602
1998-01-01	1740
1998-04-01	14167
1998-07-01	4696
1998-10-01	14747
1999-01-01	20141
1999-04-01	35830
1999-07-01	30743
1999-10-01	24454
2000-01-01	9038
2000-04-01	44747
2000-07-01	43523
2000-10-01	41624
2001-01-01	54578
2001-04-01	52425
2001-07-01	11276
2001-10-01	38535
2002-01-01	-38
2002-04-01	26517
2002-07-01	-3829
2002-10-01	-1602
2003-01-01	5172
2003-04-01	25541
2003-07-01	8577
2003-10-01	24820
2004-01-01	-3535
2004-04-01	8291
2004-07-01	-259
2004-10-01	21847
2005-01-01	3302
2005-04-01	5591
2005-07-01	-24292
2005-10-01	26507
2006-01-01	17605
2006-04-01	19535
2006-07-01	16794
2006-10-01	26168
2007-01-01	18413
2007-04-01	48467
2007-07-01	-2323
2007-10-01	25624
2008-01-01	4001
2008-04-01	46287
2008-07-01	15912
2008-10-01	9047
2009-01-01	47035
2009-04-01	82710
2009-07-01	26268
2009-10-01	27046
2010-01-01	34551
2010-04-01	11449
2010-07-01	28959
2010-10-01	33528
2011-01-01	29128
2011-04-01	43394
2011-07-01	15697
2011-10-01	23081
2012-01-01	61149
2012-04-01	40834
2012-07-01	62058
2012-10-01	75995
2013-01-01	56935
2013-04-01	49847
2013-07-01	62334
2013-10-01	95528
2014-01-01	23116
2014-04-01	59966
2014-07-01	66030
2014-10-01	53008
2015-01-01	65420
2015-04-01	55822
2015-07-01	18440
2015-10-01	38795
2016-01-01	45619
2016-04-01	70103
2016-07-01	31259
2016-10-01	35890
2017-01-01	59184
2017-04-01	53808
2017-07-01	69429
2017-10-01	32159
2018-01-01	23237
2018-04-01	48078