Quarter	Millions of US Dollars
1978-01-01	0
1978-04-01	0
1978-07-01	0
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	21
1982-04-01	20
1982-07-01	20
1982-10-01	21
1983-01-01	30
1983-04-01	110
1983-07-01	130
1983-10-01	130
1984-01-01	100
1984-04-01	20
1984-07-01	0
1984-10-01	4
1985-01-01	4
1985-04-01	44
1985-07-01	92
1985-10-01	95
1986-01-01	106
1986-04-01	55
1986-07-01	0
1986-10-01	0
1987-01-01	0
1987-04-01	68
1987-07-01	68
1987-10-01	82
1988-01-01	81
1988-04-01	75
1988-07-01	74
1988-10-01	80
1989-01-01	220
1989-04-01	445
1989-07-01	517
1989-10-01	515
1990-01-01	435
1990-04-01	141
1990-07-01	251
1990-10-01	328
1991-01-01	238
1991-04-01	241
1991-07-01	75
1991-10-01	0
1992-01-01	30
1992-04-01	32
1992-07-01	175
1992-10-01	156
1993-01-01	211
1993-04-01	213
1993-07-01	175
1993-10-01	189
1994-01-01	267
1994-04-01	272
1994-07-01	437
1994-10-01	415
1995-01-01	454
1995-04-01	453
1995-07-01	471
1995-10-01	514
1996-01-01	969
1996-04-01	966
1996-07-01	902
1996-10-01	768
1997-01-01	474
1997-04-01	490
1997-07-01	492
1997-10-01	463
1998-01-01	557
1998-04-01	734
1998-07-01	1179
1998-10-01	1048
1999-01-01	955
1999-04-01	957
1999-07-01	633
1999-10-01	939
2000-01-01	1040
2000-04-01	1508
2000-07-01	1815
2000-10-01	2445
2001-01-01	2464
2001-04-01	2762
2001-07-01	2337
2001-10-01	1458
2002-01-01	1079
2002-04-01	1124
2002-07-01	2224
2002-10-01	2549
2003-01-01	2882
2003-04-01	2715
2003-07-01	2246
2003-10-01	1894
2004-01-01	1230
2004-04-01	892
2004-07-01	1350
2004-10-01	1669
2005-01-01	1648
2005-04-01	2176
2005-07-01	1130
2005-10-01	1694
2006-01-01	1981
2006-04-01	3745
2006-07-01	4262
2006-10-01	3155
2007-01-01	2497
2007-04-01	1577
2007-07-01	1211
2007-10-01	1408
2008-01-01	1527
2008-04-01	736
2008-07-01	961
2008-10-01	571
2009-01-01	836
2009-04-01	1178
2009-07-01	920
2009-10-01	1056
2010-01-01	606
2010-04-01	696
2010-07-01	1124
2010-10-01	861
2011-01-01	856
2011-04-01	410
2011-07-01	472
2011-10-01	722
2012-01-01	1194
2012-04-01	1587
2012-07-01	1131
2012-10-01	1322
2013-01-01	827
2013-04-01	465
2013-07-01	1090
2013-10-01	725
2014-01-01	925
2014-04-01	1674
2014-07-01	1042
2014-10-01	941
2015-01-01	890
2015-04-01	206
2015-07-01	506
2015-10-01	500
2016-01-01	400
2016-04-01	1000
2016-07-01	977
2016-10-01	3039
2017-01-01	3181
2017-04-01	2660
2017-07-01	3425
2017-10-01	1327
2018-01-01	1322
2018-04-01	1290