Quarter	Millions of US Dollars
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	18
1978-07-01	18
1978-10-01	18
1979-01-01	18
1979-04-01	25
1979-07-01	26
1979-10-01	26
1980-01-01	24
1980-04-01	0
1980-07-01	0
1980-10-01	0
1981-01-01	0
1981-04-01	0
1981-07-01	0
1981-10-01	0
1982-01-01	63
1982-04-01	63
1982-07-01	62
1982-10-01	63
1983-01-01	51
1983-04-01	83
1983-07-01	158
1983-10-01	154
1984-01-01	147
1984-04-01	108
1984-07-01	96
1984-10-01	259
1985-01-01	240
1985-04-01	282
1985-07-01	385
1985-10-01	277
1986-01-01	281
1986-04-01	304
1986-07-01	158
1986-10-01	101
1987-01-01	192
1987-04-01	550
1987-07-01	625
1987-10-01	706
1988-01-01	762
1988-04-01	539
1988-07-01	706
1988-10-01	791
1989-01-01	742
1989-04-01	729
1989-07-01	688
1989-10-01	1020
1990-01-01	835
1990-04-01	647
1990-07-01	625
1990-10-01	405
1991-01-01	498
1991-04-01	630
1991-07-01	529
1991-10-01	1664
1992-01-01	1547
1992-04-01	1436
1992-07-01	2869
1992-10-01	2105
1993-01-01	2021
1993-04-01	2605
1993-07-01	1732
1993-10-01	1651
1994-01-01	1817
1994-04-01	1770
1994-07-01	1443
1994-10-01	1052
1995-01-01	1334
1995-04-01	715
1995-07-01	572
1995-10-01	489
1996-01-01	431
1996-04-01	504
1996-07-01	615
1996-10-01	416
1997-01-01	820
1997-04-01	807
1997-07-01	982
1997-10-01	970
1998-01-01	500
1998-04-01	589
1998-07-01	769
1998-10-01	1973
1999-01-01	2549
1999-04-01	2894
1999-07-01	2680
1999-10-01	1430
2000-01-01	1125
2000-04-01	1251
2000-07-01	1415
2000-10-01	1966
2001-01-01	2014
2001-04-01	3160
2001-07-01	2632
2001-10-01	3608
2002-01-01	3479
2002-04-01	3536
2002-07-01	4967
2002-10-01	4425
2003-01-01	6228
2003-04-01	5371
2003-07-01	5814
2003-10-01	5463
2004-01-01	2957
2004-04-01	2595
2004-07-01	2233
2004-10-01	3317
2005-01-01	3147
2005-04-01	4472
2005-07-01	3832
2005-10-01	3937
2006-01-01	4689
2006-04-01	5107
2006-07-01	4945
2006-10-01	3294
2007-01-01	3295
2007-04-01	5635
2007-07-01	5220
2007-10-01	6346
2008-01-01	7947
2008-04-01	4915
2008-07-01	4989
2008-10-01	3922
2009-01-01	3715
2009-04-01	2290
2009-07-01	2212
2009-10-01	2067
2010-01-01	2112
2010-04-01	3891
2010-07-01	5800
2010-10-01	5862
2011-01-01	4519
2011-04-01	2734
2011-07-01	863
2011-10-01	1689
2012-01-01	2476
2012-04-01	3724
2012-07-01	4849
2012-10-01	4674
2013-01-01	6657
2013-04-01	9505
2013-07-01	11311
2013-10-01	11393
2014-01-01	9868
2014-04-01	10609
2014-07-01	7609
2014-10-01	7729
2015-01-01	9876
2015-04-01	5290
2015-07-01	8138
2015-10-01	9682
2016-01-01	7884
2016-04-01	11459
2016-07-01	8855
2016-10-01	6704
2017-01-01	7127
2017-04-01	3665
2017-07-01	4618
2017-10-01	6054
2018-01-01	9746
2018-04-01	15899