Quarter	Millions of US Dollars
1974-04-01	17
1974-07-01	17
1974-10-01	17
1975-01-01	18
1975-04-01	17
1975-07-01	17
1975-10-01	17
1976-01-01	17
1976-04-01	17
1976-07-01	17
1976-10-01	17
1977-01-01	55
1977-04-01	92
1977-07-01	136
1977-10-01	145
1978-01-01	268
1978-04-01	276
1978-07-01	293
1978-10-01	375
1979-01-01	384
1979-04-01	361
1979-07-01	465
1979-10-01	453
1980-01-01	429
1980-04-01	468
1980-07-01	541
1980-10-01	541
1981-01-01	523
1981-04-01	490
1981-07-01	487
1981-10-01	574
1982-01-01	531
1982-04-01	518
1982-07-01	502
1982-10-01	546
1983-01-01	521
1983-04-01	516
1983-07-01	518
1983-10-01	520
1984-01-01	512
1984-04-01	489
1984-07-01	439
1984-10-01	430
1985-01-01	399
1985-04-01	400
1985-07-01	446
1985-10-01	443
1986-01-01	466
1986-04-01	501
1986-07-01	426
1986-10-01	328
1987-01-01	359
1987-04-01	288
1987-07-01	290
1987-10-01	349
1988-01-01	243
1988-04-01	226
1988-07-01	223
1988-10-01	239
1989-01-01	204
1989-04-01	188
1989-07-01	194
1989-10-01	188
1990-01-01	171
1990-04-01	1040
1990-07-01	971
1990-10-01	973
1991-01-01	969
1991-04-01	971
1991-07-01	975
1991-10-01	862
1992-01-01	862
1992-04-01	862
1992-07-01	862
1992-10-01	4211
1993-01-01	4361
1993-04-01	4361
1993-07-01	4361
1993-10-01	4361
1994-01-01	4361
1994-04-01	4361
1994-07-01	4361
1994-10-01	4361
1995-01-01	4361
1995-04-01	4361
1995-07-01	4361
1995-10-01	4361
1996-01-01	4211
1996-04-01	4211
1996-07-01	4569
1996-10-01	5244
1997-01-01	5224
1997-04-01	5250
1997-07-01	5231
1997-10-01	5180
1998-01-01	5116
1998-04-01	5575
1998-07-01	5525
1998-10-01	5554
1999-01-01	7164
1999-04-01	7722
1999-07-01	7728
1999-10-01	8402
2000-01-01	9650
2000-04-01	9324
2000-07-01	9544
2000-10-01	9458
2001-01-01	9324
2001-04-01	9444
2001-07-01	9440
2001-10-01	10123
2002-01-01	11721
2002-04-01	11394
2002-07-01	12602
2002-10-01	12853
2003-01-01	13862
2003-04-01	13845
2003-07-01	14553
2003-10-01	15931
2004-01-01	16515
2004-04-01	16751
2004-07-01	17842
2004-10-01	17973
2005-01-01	19134
2005-04-01	19687
2005-07-01	20358
2005-10-01	20043
2006-01-01	22183
2006-04-01	21814
2006-07-01	23317
2006-10-01	22053
2007-01-01	23073
2007-04-01	22951
2007-07-01	22759
2007-10-01	22834
2008-01-01	23515
2008-04-01	22741
2008-07-01	22575
2008-10-01	22607
2009-01-01	23056
2009-04-01	23165
2009-07-01	24011
2009-10-01	24966
2010-01-01	26003
2010-04-01	26029
2010-07-01	27212
2010-10-01	26887
2011-01-01	28168
2011-04-01	28233
2011-07-01	28252
2011-10-01	27606
2012-01-01	28893
2012-04-01	28934
2012-07-01	29005
2012-10-01	29684
2013-01-01	28576
2013-04-01	28371
2013-07-01	28132
2013-10-01	28013
2014-01-01	27806
2014-04-01	27891
2014-07-01	27620
2014-10-01	27532
2015-01-01	28922
2015-04-01	28897
2015-07-01	28813
2015-10-01	28790
2016-01-01	29661
2016-04-01	29676
2016-07-01	29613
2016-10-01	28946
2017-01-01	30051
2017-04-01	30036
2017-07-01	30011
2017-10-01	30062
2018-01-01	32459
2018-04-01	32349