Quarter	Millions of US Dollars
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	34
1977-10-01	50
1978-01-01	54
1978-04-01	54
1978-07-01	13
1978-10-01	0
1979-01-01	0
1979-04-01	0
1979-07-01	0
1979-10-01	0
1980-01-01	0
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	0
1982-04-01	0
1982-07-01	0
1982-10-01	0
1983-01-01	0
1983-04-01	0
1983-07-01	12
1983-10-01	13
1984-01-01	58
1984-04-01	84
1984-07-01	71
1984-10-01	101
1985-01-01	106
1985-04-01	117
1985-07-01	267
1985-10-01	566
1986-01-01	816
1986-04-01	780
1986-07-01	810
1986-10-01	480
1987-01-01	181
1987-04-01	306
1987-07-01	149
1987-10-01	163
1988-01-01	162
1988-04-01	135
1988-07-01	191
1988-10-01	431
1989-01-01	480
1989-04-01	1057
1989-07-01	1131
1989-10-01	1236
1990-01-01	1344
1990-04-01	1145
1990-07-01	1411
1990-10-01	1144
1991-01-01	1889
1991-04-01	1830
1991-07-01	1825
1991-10-01	1955
1992-01-01	1232
1992-04-01	1033
1992-07-01	995
1992-10-01	1256
1993-01-01	1548
1993-04-01	1609
1993-07-01	1973
1993-10-01	1549
1994-01-01	1421
1994-04-01	1443
1994-07-01	1835
1994-10-01	2050
1995-01-01	2904
1995-04-01	2864
1995-07-01	2454
1995-10-01	2082
1996-01-01	1717
1996-04-01	1369
1996-07-01	1479
1996-10-01	2702
1997-01-01	3535
1997-04-01	4451
1997-07-01	4310
1997-10-01	4338
1998-01-01	4229
1998-04-01	4518
1998-07-01	5088
1998-10-01	5797
1999-01-01	8282
1999-04-01	6710
1999-07-01	8559
1999-10-01	8161
2000-01-01	6206
2000-04-01	5000
2000-07-01	6156
2000-10-01	8021
2001-01-01	7737
2001-04-01	8860
2001-07-01	8661
2001-10-01	6997
2002-01-01	6864
2002-04-01	7057
2002-07-01	7584
2002-10-01	7561
2003-01-01	7885
2003-04-01	6585
2003-07-01	6776
2003-10-01	6452
2004-01-01	6157
2004-04-01	6983
2004-07-01	5882
2004-10-01	7207
2005-01-01	7771
2005-04-01	7632
2005-07-01	8338
2005-10-01	5565
2006-01-01	7114
2006-04-01	8731
2006-07-01	8365
2006-10-01	8813
2007-01-01	7408
2007-04-01	5905
2007-07-01	5571
2007-10-01	5834
2008-01-01	7494
2008-04-01	8255
2008-07-01	9139
2008-10-01	11121
2009-01-01	9483
2009-04-01	9093
2009-07-01	7156
2009-10-01	7551
2010-01-01	10468
2010-04-01	9150
2010-07-01	11944
2010-10-01	12622
2011-01-01	12177
2011-04-01	16543
2011-07-01	17524
2011-10-01	18424
2012-01-01	23647
2012-04-01	25401
2012-07-01	28200
2012-10-01	29713
2013-01-01	34361
2013-04-01	41753
2013-07-01	46591
2013-10-01	50883
2014-01-01	56954
2014-04-01	62844
2014-07-01	63808
2014-10-01	62938
2015-01-01	67280
2015-04-01	65931
2015-07-01	56760
2015-10-01	70088
2016-01-01	66388
2016-04-01	61862
2016-07-01	69800
2016-10-01	71722
2017-01-01	76494
2017-04-01	84245
2017-07-01	86312
2017-10-01	94374
2018-01-01	92883
2018-04-01	93280