Quarter	Millions of US Dollars
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	0
1978-04-01	0
1978-07-01	0
1978-10-01	0
1979-01-01	25
1979-04-01	25
1979-07-01	25
1979-10-01	25
1980-01-01	30
1980-04-01	136
1980-07-01	134
1980-10-01	129
1981-01-01	96
1981-04-01	0
1981-07-01	28
1981-10-01	49
1982-01-01	108
1982-04-01	167
1982-07-01	175
1982-10-01	172
1983-01-01	112
1983-04-01	103
1983-07-01	69
1983-10-01	95
1984-01-01	96
1984-04-01	93
1984-07-01	192
1984-10-01	233
1985-01-01	234
1985-04-01	207
1985-07-01	112
1985-10-01	36
1986-01-01	86
1986-04-01	67
1986-07-01	70
1986-10-01	61
1987-01-01	11
1987-04-01	11
1987-07-01	9
1987-10-01	8
1988-01-01	8
1988-04-01	28
1988-07-01	80
1988-10-01	78
1989-01-01	77
1989-04-01	122
1989-07-01	74
1989-10-01	72
1990-01-01	66
1990-04-01	3
1990-07-01	0
1990-10-01	111
1991-01-01	251
1991-04-01	265
1991-07-01	279
1991-10-01	410
1992-01-01	592
1992-04-01	755
1992-07-01	892
1992-10-01	900
1993-01-01	962
1993-04-01	854
1993-07-01	979
1993-10-01	964
1994-01-01	1545
1994-04-01	2016
1994-07-01	2457
1994-10-01	2976
1995-01-01	2606
1995-04-01	3304
1995-07-01	4932
1995-10-01	5375
1996-01-01	5868
1996-04-01	5070
1996-07-01	3036
1996-10-01	3064
1997-01-01	2989
1997-04-01	3643
1997-07-01	4424
1997-10-01	6997
1998-01-01	6211
1998-04-01	7495
1998-07-01	7952
1998-10-01	6106
1999-01-01	7597
1999-04-01	6288
1999-07-01	7512
1999-10-01	8464
2000-01-01	6624
2000-04-01	7021
2000-07-01	4656
2000-10-01	6834
2001-01-01	6845
2001-04-01	9262
2001-07-01	9862
2001-10-01	10916
2002-01-01	10660
2002-04-01	11521
2002-07-01	12925
2002-10-01	11672
2003-01-01	15162
2003-04-01	11580
2003-07-01	12062
2003-10-01	12750
2004-01-01	11345
2004-04-01	12470
2004-07-01	16120
2004-10-01	17399
2005-01-01	14192
2005-04-01	14898
2005-07-01	11045
2005-10-01	12961
2006-01-01	14074
2006-04-01	15688
2006-07-01	17492
2006-10-01	16189
2007-01-01	19515
2007-04-01	18976
2007-07-01	18567
2007-10-01	20047
2008-01-01	24048
2008-04-01	26521
2008-07-01	28664
2008-10-01	30079
2009-01-01	30372
2009-04-01	31139
2009-07-01	33737
2009-10-01	31667
2010-01-01	29332
2010-04-01	29449
2010-07-01	31327
2010-10-01	34094
2011-01-01	34150
2011-04-01	34673
2011-07-01	31511
2011-10-01	32331
2012-01-01	45011
2012-04-01	43209
2012-07-01	45698
2012-10-01	43985
2013-01-01	54529
2013-04-01	59124
2013-07-01	66677
2013-10-01	63311
2014-01-01	48040
2014-04-01	46213
2014-07-01	47676
2014-10-01	74879
2015-01-01	70585
2015-04-01	68532
2015-07-01	65929
2015-10-01	38695
2016-01-01	47806
2016-04-01	58365
2016-07-01	57833
2016-10-01	63305
2017-01-01	66905
2017-04-01	78308
2017-07-01	80616
2017-10-01	82156
2018-01-01	71705
2018-04-01	54869