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	42
1976-01-01	43
1976-04-01	45
1976-07-01	125
1976-10-01	150
1977-01-01	226
1977-04-01	245
1977-07-01	265
1977-10-01	347
1978-01-01	491
1978-04-01	790
1978-07-01	1189
1978-10-01	1728
1979-01-01	2190
1979-04-01	2658
1979-07-01	3094
1979-10-01	3438
1980-01-01	3256
1980-04-01	3949
1980-07-01	3674
1980-10-01	3964
1981-01-01	3988
1981-04-01	3805
1981-07-01	4286
1981-10-01	4222
1982-01-01	4298
1982-04-01	4478
1982-07-01	4679
1982-10-01	5338
1983-01-01	5952
1983-04-01	6378
1983-07-01	6243
1983-10-01	5727
1984-01-01	6118
1984-04-01	6331
1984-07-01	6915
1984-10-01	12544
1985-01-01	13327
1985-04-01	13424
1985-07-01	15586
1985-10-01	12944
1986-01-01	13613
1986-04-01	15098
1986-07-01	16673
1986-10-01	19422
1987-01-01	23451
1987-04-01	24587
1987-07-01	25704
1987-10-01	27452
1988-01-01	25197
1988-04-01	23416
1988-07-01	23847
1988-10-01	25001
1989-01-01	24523
1989-04-01	25558
1989-07-01	26914
1989-10-01	28301
1990-01-01	30833
1990-04-01	33964
1990-07-01	36526
1990-10-01	39211
1991-01-01	42379
1991-04-01	48221
1991-07-01	63011
1991-10-01	72472
1992-01-01	87366
1992-04-01	112345
1992-07-01	123950
1992-10-01	124517
1993-01-01	110411
1993-04-01	86127
1993-07-01	89564
1993-10-01	80126
1994-01-01	80246
1994-04-01	81889
1994-07-01	84848
1994-10-01	82353
1995-01-01	87114
1995-04-01	94613
1995-07-01	93644
1995-10-01	99986
1996-01-01	101211
1996-04-01	99738
1996-07-01	88580
1996-10-01	97465
1997-01-01	104443
1997-04-01	109358
1997-07-01	104179
1997-10-01	94149
1998-01-01	87332
1998-04-01	82525
1998-07-01	80118
1998-10-01	94567
1999-01-01	94705
1999-04-01	101490
1999-07-01	109952
1999-10-01	113428
2000-01-01	113455
2000-04-01	128169
2000-07-01	138473
2000-10-01	162902
2001-01-01	166976
2001-04-01	162146
2001-07-01	163790
2001-10-01	160207
2002-01-01	156274
2002-04-01	163988
2002-07-01	164382
2002-10-01	168103
2003-01-01	171243
2003-04-01	198068
2003-07-01	192330
2003-10-01	207209
2004-01-01	193773
2004-04-01	181814
2004-07-01	177794
2004-10-01	187652
2005-01-01	188010
2005-04-01	192150
2005-07-01	185575
2005-10-01	195840
2006-01-01	202921
2006-04-01	212153
2006-07-01	211249
2006-10-01	189944
2007-01-01	197931
2007-04-01	200369
2007-07-01	192806
2007-10-01	211809
2008-01-01	228423
2008-04-01	239129
2008-07-01	228385
2008-10-01	221276
2009-01-01	192799
2009-04-01	194529
2009-07-01	186285
2009-10-01	187314
2010-01-01	199024
2010-04-01	212354
2010-07-01	229451
2010-10-01	222115
2011-01-01	230074
2011-04-01	237818
2011-07-01	215645
2011-10-01	212328
2012-01-01	220385
2012-04-01	235555
2012-07-01	259388
2012-10-01	268731
2013-01-01	289410
2013-04-01	326776
2013-07-01	344591
2013-10-01	365934
2014-01-01	355206
2014-04-01	322700
2014-07-01	296227
2014-10-01	271290
2015-01-01	256358
2015-04-01	281381
2015-07-01	294390
2015-10-01	310321
2016-01-01	353864
2016-04-01	366485
2016-07-01	363113
2016-10-01	363790
2017-01-01	362064
2017-04-01	366561
2017-07-01	375259
2017-10-01	354126
2018-01-01	363464
2018-04-01	366962