Quarter	Millions of US Dollars
1971-01-01	25
1971-04-01	25
1971-07-01	25
1971-10-01	25
1972-01-01	25
1972-04-01	25
1972-07-01	25
1972-10-01	25
1973-01-01	56
1973-04-01	57
1973-07-01	105
1973-10-01	100
1974-01-01	105
1974-04-01	155
1974-07-01	154
1974-10-01	204
1975-01-01	208
1975-04-01	237
1975-07-01	217
1975-10-01	259
1976-01-01	259
1976-04-01	257
1976-07-01	282
1976-10-01	287
1977-01-01	282
1977-04-01	287
1977-07-01	350
1977-10-01	384
1978-01-01	402
1978-04-01	486
1978-07-01	541
1978-10-01	540
1979-01-01	520
1979-04-01	564
1979-07-01	621
1979-10-01	567
1980-01-01	587
1980-04-01	655
1980-07-01	645
1980-10-01	713
1981-01-01	772
1981-04-01	819
1981-07-01	749
1981-10-01	1120
1982-01-01	1263
1982-04-01	1337
1982-07-01	1406
1982-10-01	1490
1983-01-01	1742
1983-04-01	1797
1983-07-01	1817
1983-10-01	2339
1984-01-01	2444
1984-04-01	2417
1984-07-01	2679
1984-10-01	2780
1985-01-01	3217
1985-04-01	3437
1985-07-01	3831
1985-10-01	4215
1986-01-01	4777
1986-04-01	5479
1986-07-01	6705
1986-10-01	6918
1987-01-01	7037
1987-04-01	7175
1987-07-01	7040
1987-10-01	7438
1988-01-01	7362
1988-04-01	7115
1988-07-01	6614
1988-10-01	6841
1989-01-01	6256
1989-04-01	6310
1989-07-01	6522
1989-10-01	6815
1990-01-01	7014
1990-04-01	7405
1990-07-01	7689
1990-10-01	7901
1991-01-01	7266
1991-04-01	7576
1991-07-01	7925
1991-10-01	8357
1992-01-01	7975
1992-04-01	8163
1992-07-01	8978
1992-10-01	8884
1993-01-01	10602
1993-04-01	10324
1993-07-01	11216
1993-10-01	10506
1994-01-01	10291
1994-04-01	11009
1994-07-01	11022
1994-10-01	10431
1995-01-01	11650
1995-04-01	11815
1995-07-01	11272
1995-10-01	10916
1996-01-01	9737
1996-04-01	9109
1996-07-01	8943
1996-10-01	8627
1997-01-01	7847
1997-04-01	7507
1997-07-01	7355
1997-10-01	6805
1998-01-01	6621
1998-04-01	6414
1998-07-01	6725
1998-10-01	6753
1999-01-01	7006
1999-04-01	6357
1999-07-01	5716
1999-10-01	6389
2000-01-01	6408
2000-04-01	6947
2000-07-01	4651
2000-10-01	4906
2001-01-01	4249
2001-04-01	3496
2001-07-01	5124
2001-10-01	8407
2002-01-01	7491
2002-04-01	7277
2002-07-01	6092
2002-10-01	6917
2003-01-01	6356
2003-04-01	7049
2003-07-01	5039
2003-10-01	3476
2004-01-01	3052
2004-04-01	1689
2004-07-01	1039
2004-10-01	867
2005-01-01	795
2005-04-01	642
2005-07-01	639
2005-10-01	634
2006-01-01	640
2006-04-01	640
2006-07-01	638
2006-10-01	640
2007-01-01	641
2007-04-01	1605
2007-07-01	12901
2007-10-01	1668
2008-01-01	7987
2008-04-01	8470
2008-07-01	17981
2008-10-01	28242
2009-01-01	23436
2009-04-01	28510
2009-07-01	19579
2009-10-01	13096
2010-01-01	17422
2010-04-01	16834
2010-07-01	20973
2010-10-01	15863
2011-01-01	16493
2011-04-01	16697
2011-07-01	15717
2011-10-01	14814
2012-01-01	15960
2012-04-01	15385
2012-07-01	15956
2012-10-01	16350
2013-01-01	19243
2013-04-01	20071
2013-07-01	19325
2013-10-01	19383
2014-01-01	24682
2014-04-01	24231
2014-07-01	23706
2014-10-01	23766
2015-01-01	22123
2015-04-01	22229
2015-07-01	22075
2015-10-01	19928
2016-01-01	22226
2016-04-01	21106
2016-07-01	22190
2016-10-01	18674
2017-01-01	20402
2017-04-01	24062
2017-07-01	23699
2017-10-01	19508
2018-01-01	23200
2018-04-01	22180