Quarter	Millions of US Dollars
1966-01-01	0
1966-04-01	0
1966-07-01	0
1966-10-01	0
1967-01-01	0
1967-04-01	0
1967-07-01	0
1967-10-01	0
1968-01-01	0
1968-04-01	0
1968-07-01	0
1968-10-01	0
1969-01-01	0
1969-04-01	0
1969-07-01	0
1969-10-01	0
1970-01-01	0
1970-04-01	0
1970-07-01	0
1970-10-01	0
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	28
1978-04-01	27
1978-07-01	93
1978-10-01	147
1979-01-01	113
1979-04-01	141
1979-07-01	243
1979-10-01	183
1980-01-01	167
1980-04-01	153
1980-07-01	100
1980-10-01	151
1981-01-01	180
1981-04-01	212
1981-07-01	184
1981-10-01	145
1982-01-01	231
1982-04-01	464
1982-07-01	427
1982-10-01	456
1983-01-01	327
1983-04-01	288
1983-07-01	462
1983-10-01	489
1984-01-01	499
1984-04-01	289
1984-07-01	77
1984-10-01	415
1985-01-01	546
1985-04-01	896
1985-07-01	1124
1985-10-01	1372
1986-01-01	1344
1986-04-01	1178
1986-07-01	1286
1986-10-01	1106
1987-01-01	1517
1987-04-01	1345
1987-07-01	1147
1987-10-01	843
1988-01-01	864
1988-04-01	1076
1988-07-01	1635
1988-10-01	1746
1989-01-01	1267
1989-04-01	1190
1989-07-01	587
1989-10-01	1141
1990-01-01	682
1990-04-01	413
1990-07-01	582
1990-10-01	1007
1991-01-01	946
1991-04-01	2110
1991-07-01	2196
1991-10-01	1865
1992-01-01	2594
1992-04-01	2175
1992-07-01	2600
1992-10-01	2407
1993-01-01	1943
1993-04-01	1914
1993-07-01	3009
1993-10-01	3105
1994-01-01	3360
1994-04-01	3144
1994-07-01	3576
1994-10-01	3367
1995-01-01	3403
1995-04-01	2834
1995-07-01	3144
1995-10-01	3286
1996-01-01	4206
1996-04-01	4485
1996-07-01	2912
1996-10-01	4478
1997-01-01	3444
1997-04-01	2833
1997-07-01	2242
1997-10-01	3067
1998-01-01	2718
1998-04-01	2453
1998-07-01	2183
1998-10-01	2299
1999-01-01	1865
1999-04-01	1947
1999-07-01	2696
1999-10-01	2823
2000-01-01	3116
2000-04-01	2533
2000-07-01	2049
2000-10-01	2686
2001-01-01	2647
2001-04-01	3406
2001-07-01	3263
2001-10-01	3017
2002-01-01	2865
2002-04-01	2943
2002-07-01	3157
2002-10-01	2385
2003-01-01	4461
2003-04-01	4064
2003-07-01	3333
2003-10-01	3812
2004-01-01	4787
2004-04-01	6068
2004-07-01	6461
2004-10-01	9531
2005-01-01	9685
2005-04-01	7611
2005-07-01	7367
2005-10-01	7153
2006-01-01	6735
2006-04-01	7630
2006-07-01	7682
2006-10-01	6164
2007-01-01	5639
2007-04-01	6023
2007-07-01	6149
2007-10-01	8481
2008-01-01	11103
2008-04-01	6437
2008-07-01	6238
2008-10-01	4544
2009-01-01	4636
2009-04-01	5748
2009-07-01	3546
2009-10-01	3542
2010-01-01	2189
2010-04-01	1290
2010-07-01	889
2010-10-01	1877
2011-01-01	2657
2011-04-01	2427
2011-07-01	4208
2011-10-01	4923
2012-01-01	4795
2012-04-01	4563
2012-07-01	3034
2012-10-01	2985
2013-01-01	7667
2013-04-01	5550
2013-07-01	5914
2013-10-01	7078
2014-01-01	2714
2014-04-01	2732
2014-07-01	2105
2014-10-01	1493
2015-01-01	1177
2015-04-01	1539
2015-07-01	3950
2015-10-01	7710
2016-01-01	9178
2016-04-01	8890
2016-07-01	6029
2016-10-01	2131
2017-01-01	1560
2017-04-01	2828
2017-07-01	2796
2017-10-01	2905
2018-01-01	3235
2018-04-01	2125