Quarter	Millions of US Dollars
1966-01-01	20
1967-10-01	15
1971-01-01	45
1971-04-01	23
1971-07-01	15
1972-01-01	88
1972-04-01	30
1972-07-01	25
1972-10-01	51
1973-01-01	25
1973-04-01	39
1973-10-01	30
1974-01-01	22
1974-04-01	50
1974-07-01	10
1974-10-01	48
1975-01-01	230
1975-04-01	178
1975-07-01	72
1975-10-01	270
1976-01-01	186
1976-04-01	120
1976-07-01	185
1976-10-01	371
1977-01-01	157
1977-04-01	126
1977-07-01	145
1977-10-01	78
1978-01-01	116
1978-04-01	39
1978-10-01	18
1979-01-01	16
1979-04-01	50
1979-07-01	-4
1979-10-01	-30
1980-01-01	-25
1980-04-01	-95
1980-07-01	-48
1980-10-01	-111
1981-01-01	-43
1981-04-01	-37
1981-07-01	30
1981-10-01	20
1982-01-01	86
1982-04-01	-15
1982-07-01	40
1982-10-01	-17
1983-01-01	139
1983-04-01	-33
1983-07-01	-152
1983-10-01	-73
1984-01-01	49
1984-04-01	27
1984-07-01	-19
1984-10-01	-87
1985-01-01	-14
1985-04-01	7
1985-07-01	108
1985-10-01	-148
1986-01-01	343
1986-04-01	295
1986-07-01	437
1986-10-01	64
1987-01-01	105
1987-04-01	355
1987-07-01	-28
1987-10-01	-231
1988-01-01	-179
1988-04-01	289
1988-07-01	-63
1988-10-01	192
1989-01-01	332
1989-04-01	25
1989-07-01	360
1989-10-01	578
1990-01-01	49
1990-04-01	85
1990-07-01	-172
1990-10-01	-94
1991-01-01	41
1991-04-01	153
1991-07-01	54
1991-10-01	41
1992-01-01	-273
1992-04-01	469
1992-07-01	-118
1992-10-01	-208
1993-01-01	-208
1993-04-01	-351
1993-07-01	-467
1993-10-01	-79
1994-01-01	49
1994-04-01	-411
1994-07-01	-241
1994-10-01	-387
1995-01-01	55
1995-04-01	14
1995-07-01	58
1995-10-01	-97
1996-01-01	-814
1996-04-01	-631
1996-07-01	-170
1996-10-01	26
1997-01-01	414
1997-04-01	-177
1997-07-01	-276
1997-10-01	240
1998-01-01	207
1998-04-01	975
1998-07-01	-187
1998-10-01	202
1999-01-01	477
1999-04-01	1977
1999-07-01	481
1999-10-01	909
2000-01-01	302
2000-04-01	-1015
2000-07-01	1619
2000-10-01	375
2001-01-01	1755
2001-04-01	3460
2001-07-01	-977
2001-10-01	967
2002-01-01	46
2002-04-01	-27
2002-07-01	-260
2002-10-01	45
2003-01-01	-196
2003-04-01	-214
2003-07-01	-730
2003-10-01	-1761
2004-01-01	770
2004-04-01	185
2004-07-01	-894
2004-10-01	-160
2005-01-01	51
2005-04-01	2944
2005-07-01	-239
2005-10-01	439
2006-01-01	-286
2006-04-01	-2314
2006-07-01	499
2006-10-01	305
2007-01-01	1027
2007-04-01	5130
2007-07-01	-163
2007-10-01	1300
2008-01-01	-1285
2008-04-01	-613
2008-07-01	-108
2008-10-01	-31
2009-01-01	5892
2009-04-01	3961
2009-07-01	-352
2009-10-01	698
2010-01-01	30
2010-04-01	-2197
2010-07-01	-298
2010-10-01	959
2011-01-01	762
2011-04-01	4534
2011-07-01	2898
2011-10-01	2604
2012-01-01	5446
2012-04-01	957
2012-07-01	3434
2012-10-01	2218
2013-01-01	1179
2013-04-01	-663
2013-07-01	240
2013-10-01	3624
2014-01-01	832
2014-04-01	3090
2014-07-01	-362
2014-10-01	2888
2015-01-01	3178
2015-04-01	1515
2015-07-01	2297
2015-10-01	1955
2016-01-01	-1315
2016-04-01	1699
2016-07-01	1165
2016-10-01	4075
2017-01-01	5751
2017-04-01	1830
2017-07-01	1335
2017-10-01	2597
2018-01-01	2116
2018-04-01	1117