Quarter	Millions of US Dollars
1966-01-01	0
1966-04-01	0
1966-07-01	0
1966-10-01	0
1967-01-01	0
1967-04-01	0
1967-07-01	0
1967-10-01	0
1968-01-01	0
1968-04-01	0
1968-07-01	0
1968-10-01	0
1969-01-01	0
1969-04-01	0
1969-07-01	0
1969-10-01	0
1970-01-01	0
1970-04-01	0
1970-07-01	0
1970-10-01	0
1971-01-01	0
1971-04-01	0
1971-07-01	0
1971-10-01	0
1972-01-01	0
1972-04-01	0
1972-07-01	0
1972-10-01	0
1973-01-01	0
1973-04-01	0
1973-07-01	0
1973-10-01	0
1974-01-01	0
1974-04-01	0
1974-07-01	0
1974-10-01	0
1975-01-01	0
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	0
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	0
1979-04-01	0
1979-07-01	0
1979-10-01	15
1980-01-01	15
1980-04-01	15
1980-07-01	15
1980-10-01	0
1981-01-01	0
1981-04-01	0
1981-07-01	0
1981-10-01	0
1982-01-01	0
1982-04-01	0
1982-07-01	0
1982-10-01	0
1983-01-01	25
1983-04-01	25
1983-07-01	25
1983-10-01	45
1984-01-01	20
1984-04-01	20
1984-07-01	44
1984-10-01	102
1985-01-01	102
1985-04-01	112
1985-07-01	196
1985-10-01	250
1986-01-01	387
1986-04-01	489
1986-07-01	450
1986-10-01	413
1987-01-01	379
1987-04-01	324
1987-07-01	314
1987-10-01	722
1988-01-01	686
1988-04-01	447
1988-07-01	540
1988-10-01	860
1989-01-01	1201
1989-04-01	1493
1989-07-01	1531
1989-10-01	1821
1990-01-01	2380
1990-04-01	2590
1990-07-01	3129
1990-10-01	3002
1991-01-01	2911
1991-04-01	2993
1991-07-01	3040
1991-10-01	3375
1992-01-01	3319
1992-04-01	4009
1992-07-01	4915
1992-10-01	4965
1993-01-01	5132
1993-04-01	4850
1993-07-01	9244
1993-10-01	10193
1994-01-01	11668
1994-04-01	12917
1994-07-01	14465
1994-10-01	14335
1995-01-01	16943
1995-04-01	18451
1995-07-01	19281
1995-10-01	22891
1996-01-01	26389
1996-04-01	28561
1996-07-01	23244
1996-10-01	29477
1997-01-01	28538
1997-04-01	26863
1997-07-01	29832
1997-10-01	35780
1998-01-01	36920
1998-04-01	38886
1998-07-01	39732
1998-10-01	39952
1999-01-01	40158
1999-04-01	44798
1999-07-01	53350
1999-10-01	54766
2000-01-01	63743
2000-04-01	65548
2000-07-01	61545
2000-10-01	69360
2001-01-01	72482
2001-04-01	66570
2001-07-01	73791
2001-10-01	73506
2002-01-01	74385
2002-04-01	80645
2002-07-01	85028
2002-10-01	97812
2003-01-01	100788
2003-04-01	105328
2003-07-01	101516
2003-10-01	104735
2004-01-01	103560
2004-04-01	102491
2004-07-01	108175
2004-10-01	112883
2005-01-01	116169
2005-04-01	107657
2005-07-01	106397
2005-10-01	102646
2006-01-01	114866
2006-04-01	117473
2006-07-01	119551
2006-10-01	121067
2007-01-01	134347
2007-04-01	145398
2007-07-01	135155
2007-10-01	139721
2008-01-01	128074
2008-04-01	119761
2008-07-01	103224
2008-10-01	99552
2009-01-01	83878
2009-04-01	89706
2009-07-01	92805
2009-10-01	81069
2010-01-01	89165
2010-04-01	88671
2010-07-01	91194
2010-10-01	89042
2011-01-01	78020
2011-04-01	72398
2011-07-01	68814
2011-10-01	70616
2012-01-01	69969
2012-04-01	75402
2012-07-01	87376
2012-10-01	89238
2013-01-01	90613
2013-04-01	87510
2013-07-01	79778
2013-10-01	80671
2014-01-01	82232
2014-04-01	85646
2014-07-01	89577
2014-10-01	91077
2015-01-01	86015
2015-04-01	85949
2015-07-01	97054
2015-10-01	100735
2016-01-01	123616
2016-04-01	137584
2016-07-01	130055
2016-10-01	124403
2017-01-01	109680
2017-04-01	109932
2017-07-01	107829
2017-10-01	107037
2018-01-01	103882
2018-04-01	99519