Quarter	Millions of US Dollars
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	79
1977-04-01	81
1977-07-01	86
1977-10-01	100
1978-01-01	28
1978-04-01	54
1978-07-01	85
1978-10-01	91
1979-01-01	60
1979-04-01	30
1979-07-01	50
1979-10-01	110
1980-01-01	160
1980-04-01	240
1980-07-01	251
1980-10-01	322
1981-01-01	275
1981-04-01	310
1981-07-01	262
1981-10-01	130
1982-01-01	118
1982-04-01	12
1982-07-01	11
1982-10-01	47
1983-01-01	158
1983-04-01	149
1983-07-01	147
1983-10-01	195
1984-01-01	161
1984-04-01	159
1984-07-01	251
1984-10-01	465
1985-01-01	394
1985-04-01	432
1985-07-01	356
1985-10-01	202
1986-01-01	285
1986-04-01	250
1986-07-01	233
1986-10-01	748
1987-01-01	905
1987-04-01	1306
1987-07-01	1363
1987-10-01	1093
1988-01-01	1011
1988-04-01	946
1988-07-01	804
1988-10-01	866
1989-01-01	1064
1989-04-01	715
1989-07-01	799
1989-10-01	712
1990-01-01	477
1990-04-01	655
1990-07-01	593
1990-10-01	788
1991-01-01	731
1991-04-01	454
1991-07-01	329
1991-10-01	424
1992-01-01	1190
1992-04-01	1282
1992-07-01	2101
1992-10-01	1969
1993-01-01	1765
1993-04-01	1754
1993-07-01	2803
1993-10-01	2518
1994-01-01	2939
1994-04-01	3356
1994-07-01	5613
1994-10-01	6270
1995-01-01	5925
1995-04-01	6876
1995-07-01	7492
1995-10-01	8610
1996-01-01	9105
1996-04-01	8672
1996-07-01	4240
1996-10-01	8770
1997-01-01	9156
1997-04-01	9538
1997-07-01	10609
1997-10-01	10269
1998-01-01	10354
1998-04-01	12254
1998-07-01	11878
1998-10-01	13480
1999-01-01	13560
1999-04-01	16859
1999-07-01	20059
1999-10-01	22199
2000-01-01	25300
2000-04-01	34724
2000-07-01	37819
2000-10-01	38836
2001-01-01	33804
2001-04-01	29819
2001-07-01	23313
2001-10-01	21650
2002-01-01	23646
2002-04-01	26450
2002-07-01	31179
2002-10-01	31133
2003-01-01	28897
2003-04-01	27884
2003-07-01	27465
2003-10-01	30862
2004-01-01	24148
2004-04-01	23404
2004-07-01	20946
2004-10-01	25976
2005-01-01	29597
2005-04-01	29604
2005-07-01	31863
2005-10-01	33246
2006-01-01	34072
2006-04-01	40925
2006-07-01	43325
2006-10-01	39522
2007-01-01	43695
2007-04-01	39505
2007-07-01	49103
2007-10-01	47821
2008-01-01	47956
2008-04-01	52543
2008-07-01	37099
2008-10-01	39551
2009-01-01	34657
2009-04-01	31664
2009-07-01	27126
2009-10-01	29057
2010-01-01	34456
2010-04-01	32331
2010-07-01	34793
2010-10-01	28393
2011-01-01	27374
2011-04-01	27506
2011-07-01	27398
2011-10-01	31208
2012-01-01	30891
2012-04-01	32757
2012-07-01	33878
2012-10-01	36492
2013-01-01	46637
2013-04-01	52281
2013-07-01	54936
2013-10-01	53948
2014-01-01	44183
2014-04-01	37821
2014-07-01	36096
2014-10-01	34804
2015-01-01	31692
2015-04-01	35908
2015-07-01	41781
2015-10-01	46778
2016-01-01	48506
2016-04-01	43596
2016-07-01	38870
2016-10-01	41491
2017-01-01	37715
2017-04-01	40291
2017-07-01	42300
2017-10-01	39171
2018-01-01	41508
2018-04-01	44456