Quarter	Millions of US Dollars
1972-01-01	20
1972-04-01	72
1972-07-01	71
1972-10-01	91
1973-01-01	95
1973-04-01	101
1973-07-01	101
1973-10-01	97
1974-01-01	99
1974-04-01	99
1974-07-01	107
1974-10-01	110
1975-01-01	112
1975-04-01	111
1975-07-01	107
1975-10-01	107
1976-01-01	108
1976-04-01	108
1976-07-01	110
1976-10-01	159
1977-01-01	222
1977-04-01	226
1977-07-01	254
1977-10-01	333
1978-01-01	440
1978-04-01	451
1978-07-01	548
1978-10-01	571
1979-01-01	609
1979-04-01	603
1979-07-01	606
1979-10-01	592
1980-01-01	566
1980-04-01	590
1980-07-01	619
1980-10-01	617
1981-01-01	599
1981-04-01	568
1981-07-01	565
1981-10-01	583
1982-01-01	536
1982-04-01	486
1982-07-01	450
1982-10-01	479
1983-01-01	423
1983-04-01	422
1983-07-01	426
1983-10-01	429
1984-01-01	416
1984-04-01	402
1984-07-01	393
1984-10-01	386
1985-01-01	407
1985-04-01	409
1985-07-01	447
1985-10-01	400
1986-01-01	430
1986-04-01	460
1986-07-01	509
1986-10-01	410
1987-01-01	438
1987-04-01	435
1987-07-01	410
1987-10-01	479
1988-01-01	375
1988-04-01	388
1988-07-01	384
1988-10-01	329
1989-01-01	288
1989-04-01	269
1989-07-01	276
1989-10-01	270
1990-01-01	219
1990-04-01	224
1990-07-01	218
1990-10-01	203
1991-01-01	196
1991-04-01	281
1991-07-01	262
1991-10-01	279
1992-01-01	261
1992-04-01	279
1992-07-01	282
1992-10-01	261
1993-01-01	232
1993-04-01	245
1993-07-01	246
1993-10-01	235
1994-01-01	132
1994-04-01	150
1994-07-01	157
1994-10-01	191
1995-01-01	201
1995-04-01	191
1995-07-01	482
1995-10-01	684
1996-01-01	2620
1996-04-01	780
1996-07-01	4002
1996-10-01	4007
1997-01-01	4501
1997-04-01	4636
1997-07-01	5429
1997-10-01	5827
1998-01-01	5823
1998-04-01	7088
1998-07-01	7450
1998-10-01	6935
1999-01-01	7943
1999-04-01	7923
1999-07-01	7941
1999-10-01	8536
2000-01-01	8499
2000-04-01	9069
2000-07-01	9632
2000-10-01	10332
2001-01-01	11000
2001-04-01	11870
2001-07-01	12994
2001-10-01	13007
2002-01-01	13650
2002-04-01	14501
2002-07-01	15284
2002-10-01	18688
2003-01-01	20089
2003-04-01	20749
2003-07-01	20452
2003-10-01	20557
2004-01-01	19821
2004-04-01	21079
2004-07-01	24430
2004-10-01	27263
2005-01-01	26091
2005-04-01	26166
2005-07-01	26175
2005-10-01	27999
2006-01-01	30268
2006-04-01	32635
2006-07-01	32160
2006-10-01	32080
2007-01-01	31839
2007-04-01	32305
2007-07-01	32695
2007-10-01	32609
2008-01-01	32545
2008-04-01	32407
2008-07-01	32110
2008-10-01	32083
2009-01-01	34011
2009-04-01	34502
2009-07-01	34176
2009-10-01	33763
2010-01-01	35101
2010-04-01	35691
2010-07-01	36460
2010-10-01	37466
2011-01-01	38117
2011-04-01	38144
2011-07-01	39270
2011-10-01	42958
2012-01-01	42236
2012-04-01	45642
2012-07-01	46833
2012-10-01	50767
2013-01-01	49464
2013-04-01	52763
2013-07-01	55170
2013-10-01	55665
2014-01-01	55972
2014-04-01	55719
2014-07-01	58589
2014-10-01	58510
2015-01-01	60108
2015-04-01	59887
2015-07-01	59377
2015-10-01	62901
2016-01-01	64263
2016-04-01	66269
2016-07-01	66276
2016-10-01	68953
2017-01-01	72684
2017-04-01	74173
2017-07-01	79558
2017-10-01	76627
2018-01-01	76979
2018-04-01	83667