Quarter	Millions of US Dollars
1972-07-01	25
1972-10-01	25
1973-01-01	50
1973-04-01	240
1973-07-01	335
1973-10-01	422
1974-01-01	480
1974-04-01	481
1974-07-01	482
1974-10-01	494
1975-01-01	493
1975-04-01	494
1975-07-01	487
1975-10-01	490
1976-01-01	493
1976-04-01	495
1976-07-01	496
1976-10-01	503
1977-01-01	499
1977-04-01	502
1977-07-01	506
1977-10-01	520
1978-01-01	728
1978-04-01	879
1978-07-01	900
1978-10-01	894
1979-01-01	864
1979-04-01	826
1979-07-01	795
1979-10-01	791
1980-01-01	740
1980-04-01	655
1980-07-01	653
1980-10-01	532
1981-01-01	512
1981-04-01	462
1981-07-01	432
1981-10-01	407
1982-01-01	407
1982-04-01	407
1982-07-01	407
1982-10-01	407
1983-01-01	407
1983-04-01	407
1983-07-01	382
1983-10-01	382
1984-01-01	382
1984-04-01	382
1984-07-01	382
1984-10-01	382
1985-01-01	182
1985-04-01	182
1985-07-01	182
1985-10-01	2632
1986-01-01	2632
1986-04-01	2632
1986-07-01	2632
1986-10-01	2632
1987-01-01	2598
1987-04-01	2598
1987-07-01	2573
1987-10-01	2573
1988-01-01	2540
1988-04-01	2540
1988-07-01	2540
1988-10-01	40
1989-01-01	19
1989-04-01	19
1989-07-01	19
1989-10-01	19
1990-01-01	19
1990-04-01	7
1990-07-01	7
1990-10-01	7
1991-01-01	3307
1991-04-01	3124
1991-07-01	3393
1991-10-01	3694
1992-01-01	3427
1992-04-01	3698
1992-07-01	3851
1992-10-01	9742
1993-01-01	9716
1993-04-01	9457
1993-07-01	9629
1993-10-01	9245
1994-01-01	9470
1994-04-01	9765
1994-07-01	9974
1994-10-01	9940
1995-01-01	10668
1995-04-01	10670
1995-07-01	10496
1995-10-01	10458
1996-01-01	10264
1996-04-01	10075
1996-07-01	12060
1996-10-01	13986
1997-01-01	13468
1997-04-01	13262
1997-07-01	13174
1997-10-01	10037
1998-01-01	10498
1998-04-01	11110
1998-07-01	11978
1998-10-01	11958
1999-01-01	11564
1999-04-01	11389
1999-07-01	11532
1999-10-01	11269
2000-01-01	11179
2000-04-01	11174
2000-07-01	10835
2000-10-01	11066
2001-01-01	7107
2001-04-01	7105
2001-07-01	5382
2001-10-01	3377
2002-01-01	3370
2002-04-01	3399
2002-07-01	3407
2002-10-01	419
2003-01-01	411
2003-04-01	429
2003-07-01	3434
2003-10-01	3466
2004-01-01	3477
2004-04-01	3471
2004-07-01	3470
2004-10-01	3502
2005-01-01	3490
2005-04-01	3466
2005-07-01	3459
2005-10-01	3448
2006-01-01	3452
2006-04-01	3478
2006-07-01	3486
2006-10-01	3510
2007-01-01	3509
2007-04-01	3521
2007-07-01	3529
2007-10-01	3522
2008-01-01	3517
2008-04-01	3517
2008-07-01	471
2008-10-01	380
2009-01-01	372
2009-04-01	431
2009-07-01	419
2009-10-01	422
2010-01-01	394
2010-04-01	12399
2010-07-01	13109
2010-10-01	20584
2011-01-01	21318
2011-04-01	21234
2011-07-01	20660
2011-10-01	20540
2012-01-01	21238
2012-04-01	20692
2012-07-01	21484
2012-10-01	21746
2013-01-01	20371
2013-04-01	20528
2013-07-01	21729
2013-10-01	22252
2014-01-01	22394
2014-04-01	23346
2014-07-01	22500
2014-10-01	22691
2015-01-01	21556
2015-04-01	22887
2015-07-01	22082
2015-10-01	21593
2016-01-01	20957
2016-04-01	19592
2016-07-01	18923
2016-10-01	18433
2017-01-01	18706
2017-04-01	19419
2017-07-01	20029
2017-10-01	19766
2018-01-01	20796
2018-04-01	19430