Quarter	Millions of US Dollars
1966-01-01	15
1968-01-01	110
1968-04-01	145
1968-07-01	70
1968-10-01	28
1969-01-01	90
1969-10-01	8
1970-04-01	15
1970-10-01	20
1971-01-01	240
1971-04-01	95
1971-07-01	110
1971-10-01	250
1972-01-01	373
1972-04-01	500
1972-07-01	103
1972-10-01	248
1973-01-01	142
1973-04-01	39
1973-07-01	167
1973-10-01	125
1974-01-01	65
1974-04-01	10
1974-07-01	9
1974-10-01	53
1975-01-01	46
1975-04-01	157
1975-07-01	51
1975-10-01	104
1976-01-01	249
1976-04-01	55
1976-07-01	265
1976-10-01	311
1977-01-01	689
1977-04-01	573
1977-07-01	502
1977-10-01	689
1978-01-01	303
1978-04-01	100
1978-07-01	431
1978-10-01	442
1979-01-01	720
1979-04-01	948
1979-07-01	327
1979-10-01	493
1980-01-01	373
1980-04-01	1308
1980-07-01	1271
1980-10-01	1492
1981-01-01	1301
1981-04-01	1014
1981-07-01	1605
1981-10-01	1940
1982-01-01	4251
1982-04-01	4718
1982-07-01	3873
1982-10-01	3383
1983-01-01	2779
1983-04-01	2525
1983-07-01	1770
1983-10-01	3183
1984-01-01	3935
1984-04-01	2593
1984-07-01	2091
1984-10-01	1954
1985-01-01	848
1985-04-01	634
1985-07-01	1112
1985-10-01	-248
1986-01-01	609
1986-04-01	1048
1986-07-01	947
1986-10-01	756
1987-01-01	981
1987-04-01	1583
1987-07-01	565
1987-10-01	353
1988-01-01	317
1988-04-01	660
1988-07-01	2195
1988-10-01	988
1989-01-01	3043
1989-04-01	1984
1989-07-01	1627
1989-10-01	1267
1990-01-01	1499
1990-04-01	-787
1990-07-01	5464
1990-10-01	449
1991-01-01	3156
1991-04-01	384
1991-07-01	699
1991-10-01	-169
1992-01-01	-3696
1992-04-01	-1427
1992-07-01	4140
1992-10-01	250
1993-01-01	-1209
1993-04-01	-2958
1993-07-01	6817
1993-10-01	6393
1994-01-01	6288
1994-04-01	5735
1994-07-01	6962
1994-10-01	10082
1995-01-01	6067
1995-04-01	9526
1995-07-01	10722
1995-10-01	9563
1996-01-01	14183
1996-04-01	14342
1996-07-01	13365
1996-10-01	26283
1997-01-01	22531
1997-04-01	15656
1997-07-01	30640
1997-10-01	24671
1998-01-01	16445
1998-04-01	26742
1998-07-01	13724
1998-10-01	2179
1999-01-01	19720
1999-04-01	22156
1999-07-01	22142
1999-10-01	12432
2000-01-01	22443
2000-04-01	13251
2000-07-01	21024
2000-10-01	22788
2001-01-01	32896
2001-04-01	22994
2001-07-01	16858
2001-10-01	18718
2002-01-01	8156
2002-04-01	22556
2002-07-01	597
2002-10-01	316
2003-01-01	2378
2003-04-01	2227
2003-07-01	2478
2003-10-01	10813
2004-01-01	930
2004-04-01	5336
2004-07-01	6279
2004-10-01	11102
2005-01-01	18707
2005-04-01	6026
2005-07-01	17718
2005-10-01	43258
2006-01-01	55030
2006-04-01	58733
2006-07-01	81114
2006-10-01	129433
2007-01-01	106102
2007-04-01	129108
2007-07-01	50279
2007-10-01	24660
2008-01-01	-15119
2008-04-01	1902
2008-07-01	-4372
2008-10-01	-20871
2009-01-01	-14836
2009-04-01	4704
2009-07-01	2695
2009-10-01	-1742
2010-01-01	6490
2010-04-01	-11194
2010-07-01	22959
2010-10-01	16056
2011-01-01	5682
2011-04-01	18122
2011-07-01	-92
2011-10-01	11074
2012-01-01	40524
2012-04-01	23391
2012-07-01	34881
2012-10-01	45030
2013-01-01	30875
2013-04-01	57959
2013-07-01	12901
2013-10-01	37312
2014-01-01	28783
2014-04-01	61902
2014-07-01	50122
2014-10-01	19094
2015-01-01	34685
2015-04-01	48051
2015-07-01	960
2015-10-01	19453
2016-01-01	49
2016-04-01	30852
2016-07-01	26047
2016-10-01	35175
2017-01-01	49693
2017-04-01	90896
2017-07-01	70007
2017-10-01	83608
2018-01-01	87288
2018-04-01	112826