Quarter	Millions of US Dollars
1967-04-01	20
1971-01-01	31
1971-10-01	46
1972-01-01	31
1972-07-01	11
1972-10-01	46
1973-01-01	31
1973-04-01	17
1974-07-01	25
1975-01-01	21
1975-04-01	18
1975-07-01	25
1976-01-01	10
1976-04-01	67
1976-07-01	28
1976-10-01	92
1977-01-01	55
1977-04-01	52
1977-07-01	22
1977-10-01	48
1978-04-01	129
1978-07-01	22
1979-01-01	149
1979-04-01	136
1979-07-01	58
1979-10-01	38
1980-01-01	101
1980-04-01	118
1980-07-01	56
1980-10-01	69
1981-01-01	-13
1981-04-01	129
1981-10-01	114
1982-01-01	85
1982-04-01	125
1982-10-01	22
1983-01-01	117
1983-04-01	123
1983-07-01	100
1983-10-01	79
1984-01-01	47
1984-04-01	-151
1984-07-01	-45
1984-10-01	60
1985-01-01	1
1985-04-01	212
1985-07-01	49
1985-10-01	-226
1986-01-01	-83
1986-04-01	-37
1986-07-01	331
1986-10-01	365
1987-01-01	-56
1987-04-01	-242
1987-07-01	284
1987-10-01	-62
1988-01-01	223
1988-04-01	-139
1988-07-01	108
1988-10-01	304
1989-01-01	-100
1989-07-01	-160
1989-10-01	-7
1990-01-01	-131
1990-04-01	-61
1990-07-01	-257
1990-10-01	-134
1991-01-01	-77
1991-04-01	-58
1991-07-01	-4
1991-10-01	-99
1992-04-01	-16
1992-07-01	-158
1992-10-01	-153
1993-01-01	-167
1993-04-01	-79
1993-07-01	66
1993-10-01	-300
1994-01-01	-315
1994-04-01	-57
1994-07-01	-35
1994-10-01	-180
1995-01-01	-25
1995-04-01	-105
1995-07-01	-23
1995-10-01	-219
1996-01-01	-231
1996-04-01	-10
1996-07-01	-417
1996-10-01	33
1997-10-01	-35
1998-10-01	-375
1999-04-01	547
1999-07-01	511
1999-10-01	-9
2000-04-01	419
2000-07-01	-452
2000-10-01	-7
2001-10-01	446
2002-04-01	282
2003-01-01	-66
2003-04-01	631
2003-10-01	250
2004-01-01	559
2004-10-01	-648
2005-01-01	725
2005-04-01	-629
2005-10-01	-64
2006-04-01	1047
2007-04-01	281
2007-07-01	170
2008-04-01	199
2008-07-01	171
2009-04-01	-2443
2009-07-01	1604
2009-10-01	2154
2010-01-01	1056
2010-04-01	1150
2011-01-01	591
2011-04-01	445
2011-07-01	396
2011-10-01	235
2012-01-01	867
2012-04-01	-1023
2012-07-01	-948
2012-10-01	372
2013-01-01	1661
2013-04-01	910
2013-07-01	168
2013-10-01	3143
2014-01-01	2422
2014-04-01	1178
2014-07-01	4637
2014-10-01	-1831
2015-01-01	4400
2015-04-01	1179
2015-07-01	-640
2015-10-01	727
2016-01-01	274
2016-04-01	1902
2016-07-01	1873
2016-10-01	2016
2017-01-01	-35
2017-04-01	4359
2017-07-01	-304
2017-10-01	621
2018-01-01	1927
2018-04-01	1663