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	55
1973-01-01	111
1973-04-01	136
1973-07-01	209
1973-10-01	197
1974-01-01	231
1974-04-01	291
1974-07-01	304
1974-10-01	366
1975-01-01	374
1975-04-01	401
1975-07-01	367
1975-10-01	412
1976-01-01	414
1976-04-01	411
1976-07-01	441
1976-10-01	449
1977-01-01	471
1977-04-01	479
1977-07-01	544
1977-10-01	593
1978-01-01	619
1978-04-01	700
1978-07-01	773
1978-10-01	775
1979-01-01	750
1979-04-01	795
1979-07-01	843
1979-10-01	898
1980-01-01	927
1980-04-01	1015
1980-07-01	1013
1980-10-01	1066
1981-01-01	1111
1981-04-01	1143
1981-07-01	1078
1981-10-01	1456
1982-01-01	1681
1982-04-01	1746
1982-07-01	1885
1982-10-01	2001
1983-01-01	2214
1983-04-01	2278
1983-07-01	2295
1983-10-01	2914
1984-01-01	2993
1984-04-01	2957
1984-07-01	3211
1984-10-01	3407
1985-01-01	3845
1985-04-01	4067
1985-07-01	4578
1985-10-01	5146
1986-01-01	5523
1986-04-01	6237
1986-07-01	7477
1986-10-01	7593
1987-01-01	7837
1987-04-01	8003
1987-07-01	7883
1987-10-01	8604
1988-01-01	8598
1988-04-01	8205
1988-07-01	7687
1988-10-01	7755
1989-01-01	7360
1989-04-01	7315
1989-07-01	9375
1989-10-01	9715
1990-01-01	9983
1990-04-01	10504
1990-07-01	11132
1990-10-01	11225
1991-01-01	10419
1991-04-01	10638
1991-07-01	11232
1991-10-01	11468
1992-01-01	11077
1992-04-01	11254
1992-07-01	12158
1992-10-01	12321
1993-01-01	14813
1993-04-01	14954
1993-07-01	14865
1993-10-01	14210
1994-01-01	14006
1994-04-01	14736
1994-07-01	14674
1994-10-01	14035
1995-01-01	15642
1995-04-01	16038
1995-07-01	15764
1995-10-01	16557
1996-01-01	19447
1996-04-01	19132
1996-07-01	19572
1996-10-01	20354
1997-01-01	20361
1997-04-01	20636
1997-07-01	20918
1997-10-01	20326
1998-01-01	21301
1998-04-01	21727
1998-07-01	23455
1998-10-01	23230
1999-01-01	24442
1999-04-01	24599
1999-07-01	25962
1999-10-01	27562
2000-01-01	29537
2000-04-01	32778
2000-07-01	30117
2000-10-01	30530
2001-01-01	35517
2001-04-01	35060
2001-07-01	38800
2001-10-01	41226
2002-01-01	42662
2002-04-01	45105
2002-07-01	46832
2002-10-01	53752
2003-01-01	57409
2003-04-01	64613
2003-07-01	70639
2003-10-01	78630
2004-01-01	85578
2004-04-01	87611
2004-07-01	99882
2004-10-01	116406
2005-01-01	122060
2005-04-01	128879
2005-07-01	139010
2005-10-01	151194
2006-01-01	162592
2006-04-01	185496
2006-07-01	210468
2006-10-01	236227
2007-01-01	280908
2007-04-01	315142
2007-07-01	372344
2007-10-01	379836
2008-01-01	419940
2008-04-01	454449
2008-07-01	421449
2008-10-01	451496
2009-01-01	447735
2009-04-01	491226
2009-07-01	519818
2009-10-01	519301
2010-01-01	506666
2010-04-01	472554
2010-07-01	469482
2010-10-01	471079
2011-01-01	464243
2011-04-01	460047
2011-07-01	418242
2011-10-01	401197
2012-01-01	440508
2012-04-01	424948
2012-07-01	409907
2012-10-01	422055
2013-01-01	412829
2013-04-01	403629
2013-07-01	413980
2013-10-01	431848
2014-01-01	397788
2014-04-01	390348
2014-07-01	360741
2014-10-01	321881
2015-01-01	269016
2015-04-01	291679
2015-07-01	285730
2015-10-01	288773
2016-01-01	302925
2016-04-01	298502
2016-07-01	302851
2016-10-01	289187
2017-01-01	289727
2017-04-01	305506
2017-07-01	312616
2017-10-01	314203
2018-01-01	321367
2018-04-01	308374