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	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	20
1977-04-01	20
1977-07-01	21
1977-10-01	44
1978-01-01	20
1978-04-01	19
1978-07-01	21
1978-10-01	38
1979-01-01	37
1979-04-01	38
1979-07-01	40
1979-10-01	63
1980-01-01	73
1980-04-01	83
1980-07-01	82
1980-10-01	106
1981-01-01	169
1981-04-01	201
1981-07-01	413
1981-10-01	508
1982-01-01	558
1982-04-01	615
1982-07-01	408
1982-10-01	424
1983-01-01	308
1983-04-01	258
1983-07-01	412
1983-10-01	459
1984-01-01	595
1984-04-01	587
1984-07-01	1245
1984-10-01	1966
1985-01-01	2096
1985-04-01	2253
1985-07-01	1906
1985-10-01	2012
1986-01-01	2074
1986-04-01	2314
1986-07-01	2224
1986-10-01	1416
1987-01-01	1657
1987-04-01	1403
1987-07-01	2088
1987-10-01	3472
1988-01-01	3560
1988-04-01	3660
1988-07-01	3649
1988-10-01	3080
1989-01-01	2497
1989-04-01	2863
1989-07-01	2535
1989-10-01	2535
1990-01-01	3675
1990-04-01	3614
1990-07-01	4451
1990-10-01	6272
1991-01-01	7869
1991-04-01	8063
1991-07-01	7639
1991-10-01	6550
1992-01-01	3892
1992-04-01	4501
1992-07-01	5465
1992-10-01	5152
1993-01-01	5124
1993-04-01	5849
1993-07-01	8967
1993-10-01	6786
1994-01-01	8100
1994-04-01	6282
1994-07-01	6003
1994-10-01	6419
1995-01-01	6302
1995-04-01	6758
1995-07-01	7317
1995-10-01	7117
1996-01-01	6780
1996-04-01	6510
1996-07-01	6703
1996-10-01	7799
1997-01-01	8305
1997-04-01	8075
1997-07-01	9074
1997-10-01	8557
1998-01-01	7626
1998-04-01	6799
1998-07-01	5667
1998-10-01	6363
1999-01-01	6584
1999-04-01	6999
1999-07-01	8531
1999-10-01	6917
2000-01-01	5714
2000-04-01	5236
2000-07-01	6030
2000-10-01	6843
2001-01-01	7928
2001-04-01	7340
2001-07-01	6782
2001-10-01	7365
2002-01-01	7011
2002-04-01	7888
2002-07-01	8030
2002-10-01	8623
2003-01-01	10204
2003-04-01	10036
2003-07-01	9907
2003-10-01	12524
2004-01-01	14745
2004-04-01	14333
2004-07-01	12944
2004-10-01	12985
2005-01-01	12428
2005-04-01	11794
2005-07-01	11985
2005-10-01	14771
2006-01-01	15661
2006-04-01	17179
2006-07-01	18211
2006-10-01	19251
2007-01-01	21076
2007-04-01	21170
2007-07-01	19126
2007-10-01	23807
2008-01-01	29024
2008-04-01	30874
2008-07-01	31041
2008-10-01	36569
2009-01-01	36930
2009-04-01	34282
2009-07-01	52794
2009-10-01	49349
2010-01-01	41233
2010-04-01	43514
2010-07-01	25781
2010-10-01	30131
2011-01-01	33083
2011-04-01	41742
2011-07-01	42498
2011-10-01	36775
2012-01-01	42248
2012-04-01	33109
2012-07-01	33236
2012-10-01	32178
2013-01-01	30323
2013-04-01	33333
2013-07-01	34796
2013-10-01	34683
2014-01-01	27396
2014-04-01	25316
2014-07-01	23302
2014-10-01	26934
2015-01-01	25066
2015-04-01	26825
2015-07-01	25909
2015-10-01	24337
2016-01-01	24447
2016-04-01	22104
2016-07-01	21318
2016-10-01	20822
2017-01-01	23899
2017-04-01	24200
2017-07-01	22930
2017-10-01	21332
2018-01-01	19441
2018-04-01	16067