Quarter	Millions of US Dollars
1975-04-01	16
1975-07-01	16
1975-10-01	16
1976-01-01	16
1976-04-01	16
1976-07-01	16
1976-10-01	16
1977-01-01	16
1977-04-01	16
1977-07-01	59
1977-10-01	63
1978-01-01	140
1978-04-01	210
1978-07-01	225
1978-10-01	313
1979-01-01	302
1979-04-01	454
1979-07-01	523
1979-10-01	602
1980-01-01	551
1980-04-01	610
1980-07-01	749
1980-10-01	728
1981-01-01	692
1981-04-01	635
1981-07-01	638
1981-10-01	669
1982-01-01	617
1982-04-01	581
1982-07-01	562
1982-10-01	613
1983-01-01	600
1983-04-01	588
1983-07-01	584
1983-10-01	578
1984-01-01	598
1984-04-01	499
1984-07-01	437
1984-10-01	424
1985-01-01	378
1985-04-01	381
1985-07-01	439
1985-10-01	409
1986-01-01	448
1986-04-01	422
1986-07-01	452
1986-10-01	392
1987-01-01	426
1987-04-01	389
1987-07-01	373
1987-10-01	447
1988-01-01	413
1988-04-01	381
1988-07-01	373
1988-10-01	380
1989-01-01	355
1989-04-01	310
1989-07-01	281
1989-10-01	164
1990-01-01	154
1990-04-01	160
1991-10-01	500
1992-01-01	500
1992-04-01	500
1992-07-01	500
1992-10-01	750
1993-01-01	750
1993-04-01	17966
1993-07-01	18195
1993-10-01	27965
1994-01-01	28349
1994-04-01	28264
1994-07-01	28996
1994-10-01	30358
1995-01-01	30474
1995-04-01	32416
1995-07-01	34011
1995-10-01	35885
1996-01-01	38096
1996-04-01	40881
1996-07-01	41931
1996-10-01	44847
1997-01-01	48248
1997-04-01	49155
1997-07-01	52746
1997-10-01	53151
1998-01-01	55256
1998-04-01	59171
1998-07-01	62974
1998-10-01	57602
1999-01-01	57858
1999-04-01	60733
1999-07-01	63322
1999-10-01	65450
2000-01-01	69114
2000-04-01	72562
2000-07-01	72765
2000-10-01	73661
2001-01-01	73577
2001-04-01	78155
2001-07-01	79480
2001-10-01	78520
2002-01-01	76986
2002-04-01	80327
2002-07-01	79986
2002-10-01	81703
2003-01-01	82381
2003-04-01	83720
2003-07-01	84398
2003-10-01	86970
2004-01-01	86069
2004-04-01	83534
2004-07-01	83410
2004-10-01	86728
2005-01-01	84944
2005-04-01	52935
2005-07-01	52753
2005-10-01	51907
2006-01-01	52495
2006-04-01	53221
2006-07-01	52921
2006-10-01	53989
2007-01-01	53811
2007-04-01	54107
2007-07-01	54874
2007-10-01	55577
2008-01-01	56139
2008-04-01	55447
2008-07-01	52740
2008-10-01	45713
2009-01-01	44286
2009-04-01	44909
2009-07-01	45772
2009-10-01	45118
2010-01-01	43290
2010-04-01	42547
2010-07-01	45015
2010-10-01	45093
2011-01-01	47197
2011-04-01	47269
2011-07-01	45106
2011-10-01	44282
2012-01-01	44818
2012-04-01	43597
2012-07-01	44245
2012-10-01	44553
2013-01-01	43900
2013-04-01	44320
2013-07-01	44998
2013-10-01	45428
2014-01-01	45408
2014-04-01	45163
2014-07-01	43357
2014-10-01	42088
2015-01-01	40958
2015-04-01	40912
2015-07-01	40919
2015-10-01	39293
2016-01-01	41332
2016-04-01	60476
2016-07-01	64493
2016-10-01	67275
2017-01-01	78068
2017-04-01	91996
2017-07-01	93360
2017-10-01	97550
2018-01-01	107279
2018-04-01	103206