Quarter	Millions of US Dollars
1969-10-01	0
1970-01-01	0
1970-04-01	0
1970-07-01	0
1970-10-01	0
1971-01-01	0
1971-04-01	0
1971-07-01	0
1971-10-01	0
1972-01-01	0
1972-04-01	0
1972-07-01	0
1972-10-01	0
1973-01-01	0
1973-04-01	0
1973-07-01	0
1973-10-01	0
1974-01-01	0
1974-04-01	0
1974-07-01	0
1974-10-01	0
1975-01-01	0
1975-04-01	0
1975-07-01	0
1975-10-01	0
1976-01-01	0
1976-04-01	0
1976-07-01	0
1976-10-01	0
1977-01-01	0
1977-04-01	0
1977-07-01	0
1977-10-01	0
1978-01-01	0
1978-04-01	0
1978-07-01	39
1978-10-01	62
1979-01-01	60
1979-04-01	98
1979-07-01	227
1979-10-01	373
1980-01-01	342
1980-04-01	350
1980-07-01	229
1980-10-01	351
1981-01-01	442
1981-04-01	527
1981-07-01	641
1981-10-01	564
1982-01-01	509
1982-04-01	455
1982-07-01	315
1982-10-01	494
1983-01-01	480
1983-04-01	454
1983-07-01	454
1983-10-01	182
1984-01-01	450
1984-04-01	775
1984-07-01	1130
1984-10-01	1778
1985-01-01	1687
1985-04-01	2194
1985-07-01	2456
1985-10-01	2780
1986-01-01	3045
1986-04-01	2636
1986-07-01	2710
1986-10-01	2052
1987-01-01	2444
1987-04-01	2562
1987-07-01	2680
1987-10-01	3163
1988-01-01	2910
1988-04-01	2862
1988-07-01	2452
1988-10-01	2278
1989-01-01	1685
1989-04-01	1457
1989-07-01	1716
1989-10-01	1622
1990-01-01	2021
1990-04-01	1921
1990-07-01	2479
1990-10-01	2608
1991-01-01	3832
1991-04-01	5066
1991-07-01	5117
1991-10-01	5856
1992-01-01	4951
1992-04-01	4961
1992-07-01	4603
1992-10-01	4416
1993-01-01	4201
1993-04-01	3953
1993-07-01	4209
1993-10-01	3407
1994-01-01	2943
1994-04-01	3264
1994-07-01	3247
1994-10-01	3858
1995-01-01	6824
1995-04-01	7447
1995-07-01	7942
1995-10-01	7558
1996-01-01	5059
1996-04-01	4597
1996-07-01	3575
1996-10-01	3814
1997-01-01	6028
1997-04-01	6456
1997-07-01	5695
1997-10-01	6563
1998-01-01	5737
1998-04-01	6130
1998-07-01	6739
1998-10-01	7001
1999-01-01	5493
1999-04-01	5072
1999-07-01	5159
1999-10-01	4573
2000-01-01	5523
2000-04-01	7032
2000-07-01	7531
2000-10-01	7978
2001-01-01	7082
2001-04-01	9009
2001-07-01	8727
2001-10-01	9381
2002-01-01	9878
2002-04-01	9442
2002-07-01	8544
2002-10-01	8439
2003-01-01	8469
2003-04-01	6955
2003-07-01	5871
2003-10-01	6563
2004-01-01	7370
2004-04-01	6205
2004-07-01	8144
2004-10-01	7892
2005-01-01	8070
2005-04-01	10852
2005-07-01	9409
2005-10-01	10405
2006-01-01	8608
2006-04-01	7982
2006-07-01	7186
2006-10-01	5042
2007-01-01	9934
2007-04-01	10849
2007-07-01	13377
2007-10-01	14591
2008-01-01	8064
2008-04-01	6075
2008-07-01	7251
2008-10-01	6544
2009-01-01	8093
2009-04-01	7786
2009-07-01	6201
2009-10-01	8551
2010-01-01	8707
2010-04-01	13454
2010-07-01	21689
2010-10-01	21651
2011-01-01	20502
2011-04-01	19036
2011-07-01	12918
2011-10-01	12601
2012-01-01	14990
2012-04-01	12439
2012-07-01	12960
2012-10-01	14813
2013-01-01	11494
2013-04-01	20169
2013-07-01	19700
2013-10-01	17952
2014-01-01	19164
2014-04-01	15734
2014-07-01	16650
2014-10-01	16553
2015-01-01	15421
2015-04-01	14700
2015-07-01	13574
2015-10-01	16663
2016-01-01	16989
2016-04-01	22060
2016-07-01	24336
2016-10-01	27652
2017-01-01	27541
2017-04-01	24125
2017-07-01	23700
2017-10-01	17890
2018-01-01	18388
2018-04-01	18703