Quarter	Millions of US Dollars
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	14
1978-10-01	15
1979-01-01	82
1979-04-01	82
1979-07-01	92
1979-10-01	111
1980-01-01	36
1980-04-01	90
1980-07-01	68
1980-10-01	86
1981-01-01	83
1981-04-01	44
1981-07-01	44
1981-10-01	54
1982-01-01	54
1982-04-01	50
1982-07-01	50
1982-10-01	42
1983-01-01	41
1983-04-01	79
1983-07-01	135
1983-10-01	121
1984-01-01	183
1984-04-01	208
1984-07-01	146
1984-10-01	409
1985-01-01	434
1985-04-01	377
1985-07-01	537
1985-10-01	296
1986-01-01	266
1986-04-01	411
1986-07-01	476
1986-10-01	453
1987-01-01	514
1987-04-01	449
1987-07-01	248
1987-10-01	408
1988-01-01	302
1988-04-01	371
1988-07-01	470
1988-10-01	386
1989-01-01	386
1989-04-01	212
1989-07-01	604
1989-10-01	623
1990-01-01	861
1990-04-01	911
1990-07-01	496
1990-10-01	465
1991-01-01	486
1991-04-01	445
1991-07-01	781
1991-10-01	737
1992-01-01	609
1992-04-01	1068
1992-07-01	1240
1992-10-01	1132
1993-01-01	1288
1993-04-01	853
1993-07-01	430
1993-10-01	350
1994-01-01	367
1994-04-01	529
1994-07-01	573
1994-10-01	917
1995-01-01	706
1995-04-01	701
1995-07-01	985
1995-10-01	629
1996-01-01	624
1996-04-01	758
1996-07-01	400
1996-10-01	536
1997-01-01	620
1997-04-01	701
1997-07-01	958
1997-10-01	876
1998-01-01	651
1998-04-01	760
1998-07-01	1103
1998-10-01	1514
1999-01-01	1319
1999-04-01	1317
1999-07-01	1330
1999-10-01	1249
2000-01-01	1522
2000-04-01	1631
2000-07-01	3133
2000-10-01	2959
2001-01-01	1685
2001-04-01	1777
2001-07-01	983
2001-10-01	921
2002-01-01	1127
2002-04-01	1408
2002-07-01	1205
2002-10-01	1101
2003-01-01	683
2003-04-01	612
2003-07-01	821
2003-10-01	1462
2004-01-01	1672
2004-04-01	1787
2004-07-01	1634
2004-10-01	946
2005-01-01	1085
2005-04-01	960
2005-07-01	865
2005-10-01	1068
2006-01-01	2396
2006-04-01	3146
2006-07-01	3410
2006-10-01	2886
2007-01-01	1804
2007-04-01	1531
2007-07-01	1543
2007-10-01	1675
2008-01-01	2693
2008-04-01	2289
2008-07-01	2121
2008-10-01	1760
2009-01-01	971
2009-04-01	2007
2009-07-01	2170
2009-10-01	2247
2010-01-01	1469
2010-04-01	1366
2010-07-01	1980
2010-10-01	2030
2011-01-01	2132
2011-04-01	2142
2011-07-01	1942
2011-10-01	1871
2012-01-01	2770
2012-04-01	2466
2012-07-01	2492
2012-10-01	1721
2013-01-01	1854
2013-04-01	3142
2013-07-01	2995
2013-10-01	4936
2014-01-01	5538
2014-04-01	5043
2014-07-01	5318
2014-10-01	4089
2015-01-01	2490
2015-04-01	2862
2015-07-01	2561
2015-10-01	2411
2016-01-01	2343
2016-04-01	2949
2016-07-01	5709
2016-10-01	8501
2017-01-01	10780
2017-04-01	11683
2017-07-01	8552
2017-10-01	5681
2018-01-01	4533
2018-04-01	5130