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	273
1979-10-01	463
1980-01-01	454
1980-04-01	455
1980-07-01	392
1980-10-01	289
1981-01-01	257
1981-04-01	456
1981-07-01	501
1981-10-01	445
1982-01-01	604
1982-04-01	918
1982-07-01	1140
1982-10-01	1239
1983-01-01	1211
1983-04-01	980
1983-07-01	925
1983-10-01	1288
1984-01-01	3373
1984-04-01	3339
1984-07-01	3414
1984-10-01	5024
1985-01-01	4000
1985-04-01	4347
1985-07-01	4647
1985-10-01	4079
1986-01-01	3566
1986-04-01	3700
1986-07-01	4157
1986-10-01	3449
1987-01-01	3595
1987-04-01	5566
1987-07-01	5206
1987-10-01	5565
1988-01-01	5494
1988-04-01	3603
1988-07-01	3146
1988-10-01	3023
1989-01-01	2923
1989-04-01	4298
1989-07-01	5099
1989-10-01	5343
1990-01-01	6561
1990-04-01	5268
1990-07-01	5577
1990-10-01	7264
1991-01-01	6919
1991-04-01	6643
1991-07-01	7132
1991-10-01	5678
1992-01-01	4865
1992-04-01	6151
1992-07-01	7231
1992-10-01	7376
1993-01-01	8765
1993-04-01	7567
1993-07-01	16411
1993-10-01	16327
1994-01-01	17886
1994-04-01	19734
1994-07-01	19748
1994-10-01	24275
1995-01-01	23983
1995-04-01	24269
1995-07-01	25454
1995-10-01	24247
1996-01-01	25097
1996-04-01	26426
1996-07-01	22079
1996-10-01	26174
1997-01-01	25096
1997-04-01	27891
1997-07-01	29073
1997-10-01	27393
1998-01-01	27849
1998-04-01	28564
1998-07-01	28212
1998-10-01	25821
1999-01-01	23066
1999-04-01	23607
1999-07-01	28259
1999-10-01	27566
2000-01-01	29043
2000-04-01	28524
2000-07-01	26869
2000-10-01	27007
2001-01-01	25046
2001-04-01	24132
2001-07-01	23956
2001-10-01	24489
2002-01-01	25833
2002-04-01	28263
2002-07-01	30083
2002-10-01	26385
2003-01-01	26849
2003-04-01	26375
2003-07-01	25025
2003-10-01	29995
2004-01-01	32646
2004-04-01	30328
2004-07-01	35668
2004-10-01	40051
2005-01-01	40138
2005-04-01	50682
2005-07-01	52059
2005-10-01	48889
2006-01-01	52824
2006-04-01	53146
2006-07-01	52177
2006-10-01	54062
2007-01-01	64081
2007-04-01	68026
2007-07-01	71012
2007-10-01	88846
2008-01-01	96882
2008-04-01	102977
2008-07-01	106869
2008-10-01	85332
2009-01-01	83320
2009-04-01	106254
2009-07-01	107441
2009-10-01	105739
2010-01-01	117405
2010-04-01	93740
2010-07-01	104208
2010-10-01	111298
2011-01-01	104686
2011-04-01	99774
2011-07-01	104245
2011-10-01	102819
2012-01-01	104776
2012-04-01	112372
2012-07-01	107874
2012-10-01	117184
2013-01-01	118035
2013-04-01	125431
2013-07-01	136712
2013-10-01	131537
2014-01-01	122380
2014-04-01	117159
2014-07-01	114513
2014-10-01	115934
2015-01-01	103926
2015-04-01	104362
2015-07-01	108990
2015-10-01	107064
2016-01-01	110747
2016-04-01	111054
2016-07-01	113324
2016-10-01	115842
2017-01-01	117388
2017-04-01	116206
2017-07-01	112099
2017-10-01	113214
2018-01-01	108636
2018-04-01	105567