Quarter	Millions of US Dollars
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	36
1973-07-01	46
1973-10-01	41
1974-01-01	41
1974-04-01	10
1974-07-01	0
1974-10-01	0
1975-01-01	39
1975-04-01	39
1975-07-01	129
1975-10-01	131
1976-01-01	576
1976-04-01	576
1976-07-01	487
1976-10-01	511
1977-01-01	20
1977-04-01	20
1977-07-01	21
1977-10-01	0
1978-01-01	877
1978-04-01	1083
1978-07-01	2074
1978-10-01	2579
1979-01-01	1618
1979-04-01	1618
1979-07-01	1462
1979-10-01	1670
1980-01-01	1642
1980-04-01	1947
1980-07-01	1370
1980-10-01	999
1981-01-01	2124
1981-04-01	3004
1981-07-01	3358
1981-10-01	3774
1982-01-01	3438
1982-04-01	2665
1982-07-01	3133
1982-10-01	3283
1983-01-01	3052
1983-04-01	2888
1983-07-01	2936
1983-10-01	3076
1984-01-01	3782
1984-04-01	3769
1984-07-01	5658
1984-10-01	9485
1985-01-01	8956
1985-04-01	10337
1985-07-01	11384
1985-10-01	9800
1986-01-01	10705
1986-04-01	11259
1986-07-01	11320
1986-10-01	10611
1987-01-01	11884
1987-04-01	11833
1987-07-01	11468
1987-10-01	12837
1988-01-01	12211
1988-04-01	11153
1988-07-01	9874
1988-10-01	10949
1989-01-01	9951
1989-04-01	9683
1989-07-01	9920
1989-10-01	9383
1990-01-01	10817
1990-04-01	10762
1990-07-01	10965
1990-10-01	13407
1991-01-01	12853
1991-04-01	17139
1991-07-01	21657
1991-10-01	23501
1992-01-01	25964
1992-04-01	25810
1992-07-01	25978
1992-10-01	24050
1993-01-01	24926
1993-04-01	23578
1993-07-01	28882
1993-10-01	28648
1994-01-01	26196
1994-04-01	27908
1994-07-01	27116
1994-10-01	30771
1995-01-01	35132
1995-04-01	33401
1995-07-01	35423
1995-10-01	38353
1996-01-01	39224
1996-04-01	41291
1996-07-01	39992
1996-10-01	45217
1997-01-01	45051
1997-04-01	46481
1997-07-01	45833
1997-10-01	43665
1998-01-01	44434
1998-04-01	45871
1998-07-01	52450
1998-10-01	54286
1999-01-01	53134
1999-04-01	54983
1999-07-01	56217
1999-10-01	50425
2000-01-01	52523
2000-04-01	54052
2000-07-01	47420
2000-10-01	56686
2001-01-01	53886
2001-04-01	52453
2001-07-01	56796
2001-10-01	59530
2002-01-01	65656
2002-04-01	70230
2002-07-01	65470
2002-10-01	63890
2003-01-01	48976
2003-04-01	55820
2003-07-01	60353
2003-10-01	71479
2004-01-01	83079
2004-04-01	75108
2004-07-01	74975
2004-10-01	77394
2005-01-01	76289
2005-04-01	78517
2005-07-01	89187
2005-10-01	85121
2006-01-01	96752
2006-04-01	93821
2006-07-01	84607
2006-10-01	97051
2007-01-01	91064
2007-04-01	99047
2007-07-01	103240
2007-10-01	104390
2008-01-01	111044
2008-04-01	104712
2008-07-01	103117
2008-10-01	93813
2009-01-01	95702
2009-04-01	89450
2009-07-01	103103
2009-10-01	115742
2010-01-01	110572
2010-04-01	115388
2010-07-01	104007
2010-10-01	120213
2011-01-01	123420
2011-04-01	128163
2011-07-01	143096
2011-10-01	135359
2012-01-01	214082
2012-04-01	211318
2012-07-01	217040
2012-10-01	236000
2013-01-01	177958
2013-04-01	217561
2013-07-01	219032
2013-10-01	205248
2014-01-01	212674
2014-04-01	184677
2014-07-01	206025
2014-10-01	219193
2015-01-01	217853
2015-04-01	227722
2015-07-01	240480
2015-10-01	246323
2016-01-01	257402
2016-04-01	259068
2016-07-01	244388
2016-10-01	232398
2017-01-01	240272
2017-04-01	250414
2017-07-01	259750
2017-10-01	276137
2018-01-01	299813
2018-04-01	296523