Quarter	Millions of US Dollars
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	0
1983-10-01	0
1984-01-01	0
1984-04-01	0
1984-07-01	25
1984-10-01	25
1985-01-01	25
1985-04-01	25
1985-07-01	0
1985-10-01	0
1986-01-01	0
1986-04-01	0
1986-07-01	0
1986-10-01	0
1987-01-01	0
1987-04-01	0
1987-07-01	0
1987-10-01	0
1988-01-01	0
1988-04-01	0
1988-07-01	0
1988-10-01	0
1989-01-01	0
1989-04-01	0
1989-07-01	38
1989-10-01	38
1990-01-01	38
1990-04-01	39
1990-07-01	0
1990-10-01	100
1991-01-01	301
1991-04-01	459
1991-07-01	647
1991-10-01	987
1992-01-01	978
1992-04-01	1122
1992-07-01	1166
1992-10-01	1016
1993-01-01	860
1993-04-01	574
1993-07-01	406
1993-10-01	100
1994-01-01	302
1994-04-01	516
1994-07-01	518
1994-10-01	1364
1995-01-01	2267
1995-04-01	2425
1995-07-01	2764
1995-10-01	2122
1996-01-01	1286
1996-04-01	1245
1996-07-01	1404
1996-10-01	1411
1997-01-01	1368
1997-04-01	2120
1997-07-01	2292
1997-10-01	2367
1998-01-01	2722
1998-04-01	2295
1998-07-01	1829
1998-10-01	2157
1999-01-01	1922
1999-04-01	1692
1999-07-01	2045
1999-10-01	1372
2000-01-01	1248
2000-04-01	1123
2000-07-01	2065
2000-10-01	2597
2001-01-01	2397
2001-04-01	3493
2001-07-01	2380
2001-10-01	3033
2002-01-01	3759
2002-04-01	3096
2002-07-01	2913
2002-10-01	2369
2003-01-01	2590
2003-04-01	3155
2003-07-01	3483
2003-10-01	4363
2004-01-01	3720
2004-04-01	3248
2004-07-01	3321
2004-10-01	3414
2005-01-01	3317
2005-04-01	3952
2005-07-01	3802
2005-10-01	3422
2006-01-01	3654
2006-04-01	3825
2006-07-01	3460
2006-10-01	3386
2007-01-01	3927
2007-04-01	2860
2007-07-01	3065
2007-10-01	4162
2008-01-01	3466
2008-04-01	4947
2008-07-01	6317
2008-10-01	7252
2009-01-01	6598
2009-04-01	6777
2009-07-01	6864
2009-10-01	5982
2010-01-01	5421
2010-04-01	7305
2010-07-01	8014
2010-10-01	9638
2011-01-01	13594
2011-04-01	16494
2011-07-01	17165
2011-10-01	22194
2012-01-01	29771
2012-04-01	32391
2012-07-01	33905
2012-10-01	42176
2013-01-01	51946
2013-04-01	66495
2013-07-01	79672
2013-10-01	88168
2014-01-01	103640
2014-04-01	110603
2014-07-01	115018
2014-10-01	115051
2015-01-01	117825
2015-04-01	126139
2015-07-01	117146
2015-10-01	134290
2016-01-01	126275
2016-04-01	142154
2016-07-01	145744
2016-10-01	158271
2017-01-01	172080
2017-04-01	185659
2017-07-01	199116
2017-10-01	215751
2018-01-01	220920
2018-04-01	236971