Quarter	Millions of US Dollars
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	10
1977-07-01	11
1977-10-01	12
1978-01-01	13
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	0
1979-04-01	18
1979-07-01	19
1979-10-01	19
1980-01-01	30
1980-04-01	100
1980-07-01	100
1980-10-01	99
1981-01-01	111
1981-04-01	100
1981-07-01	100
1981-10-01	178
1982-01-01	176
1982-04-01	99
1982-07-01	98
1982-10-01	25
1983-01-01	0
1983-04-01	98
1983-07-01	97
1983-10-01	130
1984-01-01	131
1984-04-01	182
1984-07-01	230
1984-10-01	546
1985-01-01	1407
1985-04-01	1463
1985-07-01	1470
1985-10-01	1550
1986-01-01	697
1986-04-01	1048
1986-07-01	1116
1986-10-01	893
1987-01-01	1664
1987-04-01	1150
1987-07-01	1626
1987-10-01	3103
1988-01-01	3710
1988-04-01	4418
1988-07-01	3876
1988-10-01	4537
1989-01-01	3393
1989-04-01	3127
1989-07-01	3333
1989-10-01	3494
1990-01-01	3396
1990-04-01	3375
1990-07-01	3760
1990-10-01	1810
1991-01-01	2763
1991-04-01	2654
1991-07-01	2539
1991-10-01	3093
1992-01-01	2359
1992-04-01	4135
1992-07-01	5334
1992-10-01	4563
1993-01-01	4104
1993-04-01	3186
1993-07-01	4443
1993-10-01	6497
1994-01-01	5999
1994-04-01	6189
1994-07-01	5936
1994-10-01	5230
1995-01-01	4330
1995-04-01	6342
1995-07-01	6970
1995-10-01	7000
1996-01-01	5787
1996-04-01	5461
1996-07-01	5390
1996-10-01	7154
1997-01-01	10339
1997-04-01	8426
1997-07-01	9802
1997-10-01	8286
1998-01-01	10780
1998-04-01	10509
1998-07-01	11648
1998-10-01	12384
1999-01-01	5737
1999-04-01	8066
1999-07-01	6109
1999-10-01	6020
2000-01-01	9458
2000-04-01	17260
2000-07-01	15203
2000-10-01	16551
2001-01-01	16434
2001-04-01	18883
2001-07-01	19212
2001-10-01	19796
2002-01-01	17307
2002-04-01	22875
2002-07-01	28327
2002-10-01	33879
2003-01-01	43052
2003-04-01	43922
2003-07-01	42612
2003-10-01	44332
2004-01-01	48572
2004-04-01	52887
2004-07-01	51435
2004-10-01	53624
2005-01-01	49726
2005-04-01	46321
2005-07-01	42902
2005-10-01	52564
2006-01-01	51840
2006-04-01	43874
2006-07-01	58202
2006-10-01	49376
2007-01-01	52313
2007-04-01	70877
2007-07-01	86441
2007-10-01	93914
2008-01-01	109152
2008-04-01	105506
2008-07-01	81888
2008-10-01	76837
2009-01-01	89838
2009-04-01	96780
2009-07-01	91347
2009-10-01	95967
2010-01-01	98756
2010-04-01	99711
2010-07-01	119284
2010-10-01	106889
2011-01-01	145499
2011-04-01	151211
2011-07-01	152358
2011-10-01	165619
2012-01-01	144581
2012-04-01	122716
2012-07-01	115712
2012-10-01	102323
2013-01-01	104030
2013-04-01	116107
2013-07-01	139903
2013-10-01	128982
2014-01-01	111189
2014-04-01	93004
2014-07-01	79366
2014-10-01	85837
2015-01-01	90609
2015-04-01	94685
2015-07-01	103135
2015-10-01	98765
2016-01-01	85703
2016-04-01	90850
2016-07-01	73011
2016-10-01	70327
2017-01-01	76197
2017-04-01	74471
2017-07-01	73451
2017-10-01	64797
2018-01-01	61913
2018-04-01	58651