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	4
1977-01-01	4
1977-04-01	4
1977-07-01	4
1977-10-01	30
1978-01-01	32
1978-04-01	32
1978-07-01	58
1978-10-01	66
1979-01-01	121
1979-04-01	220
1979-07-01	265
1979-10-01	399
1980-01-01	399
1980-04-01	392
1980-07-01	338
1980-10-01	264
1981-01-01	164
1981-04-01	140
1981-07-01	180
1981-10-01	136
1982-01-01	168
1982-04-01	276
1982-07-01	407
1982-10-01	431
1983-01-01	451
1983-04-01	369
1983-07-01	212
1983-10-01	260
1984-01-01	350
1984-04-01	335
1984-07-01	298
1984-10-01	549
1985-01-01	499
1985-04-01	484
1985-07-01	713
1985-10-01	468
1986-01-01	555
1986-04-01	580
1986-07-01	427
1986-10-01	508
1987-01-01	716
1987-04-01	824
1987-07-01	944
1987-10-01	809
1988-01-01	615
1988-04-01	616
1988-07-01	443
1988-10-01	484
1989-01-01	259
1989-04-01	366
1989-07-01	521
1989-10-01	732
1990-01-01	1117
1990-04-01	992
1990-07-01	910
1990-10-01	928
1991-01-01	716
1991-04-01	761
1991-07-01	875
1991-10-01	866
1992-01-01	770
1992-04-01	949
1992-07-01	1841
1992-10-01	1642
1993-01-01	1474
1993-04-01	1439
1993-07-01	1040
1993-10-01	1304
1994-01-01	1461
1994-04-01	1378
1994-07-01	1205
1994-10-01	1007
1995-01-01	1594
1995-04-01	2046
1995-07-01	2079
1995-10-01	2240
1996-01-01	1387
1996-04-01	1265
1996-07-01	1295
1996-10-01	1281
1997-01-01	1634
1997-04-01	1446
1997-07-01	913
1997-10-01	988
1998-01-01	1505
1998-04-01	1812
1998-07-01	1848
1998-10-01	1806
1999-01-01	1990
1999-04-01	2596
1999-07-01	2220
1999-10-01	2317
2000-01-01	2537
2000-04-01	1599
2000-07-01	2283
2000-10-01	2419
2001-01-01	2006
2001-04-01	2397
2001-07-01	1651
2001-10-01	1522
2002-01-01	1168
2002-04-01	1558
2002-07-01	1922
2002-10-01	3627
2003-01-01	3591
2003-04-01	3088
2003-07-01	3271
2003-10-01	1880
2004-01-01	2210
2004-04-01	2094
2004-07-01	1759
2004-10-01	1880
2005-01-01	2901
2005-04-01	5863
2005-07-01	4969
2005-10-01	5898
2006-01-01	5754
2006-04-01	3257
2006-07-01	3871
2006-10-01	3346
2007-01-01	3077
2007-04-01	4274
2007-07-01	4294
2007-10-01	5217
2008-01-01	3533
2008-04-01	3076
2008-07-01	3178
2008-10-01	2817
2009-01-01	3196
2009-04-01	4332
2009-07-01	5342
2009-10-01	5708
2010-01-01	6018
2010-04-01	3517
2010-07-01	2947
2010-10-01	2190
2011-01-01	1639
2011-04-01	3717
2011-07-01	4590
2011-10-01	6039
2012-01-01	7213
2012-04-01	8264
2012-07-01	9094
2012-10-01	9130
2013-01-01	10256
2013-04-01	9175
2013-07-01	9406
2013-10-01	9415
2014-01-01	7475
2014-04-01	7599
2014-07-01	6923
2014-10-01	6637
2015-01-01	7273
2015-04-01	8060
2015-07-01	8575
2015-10-01	7678
2016-01-01	8584
2016-04-01	9956
2016-07-01	10318
2016-10-01	10367
2017-01-01	9171
2017-04-01	7857
2017-07-01	8426
2017-10-01	8368
2018-01-01	9374
2018-04-01	11825