Quarter	Millions of US Dollars
1976-04-01	24
1976-07-01	24
1976-10-01	24
1977-01-01	24
1977-04-01	24
1977-07-01	24
1977-10-01	25
1978-01-01	25
1978-04-01	25
1978-07-01	26
1978-10-01	26
1979-01-01	25
1979-04-01	25
1979-07-01	25
1979-10-01	26
1980-01-01	25
1980-04-01	26
1980-07-01	26
1980-10-01	26
1981-01-01	26
1981-04-01	25
1981-07-01	25
1981-10-01	25
1982-01-01	24
1982-04-01	24
1982-07-01	24
1982-10-01	24
1983-01-01	24
1983-04-01	24
1983-07-01	24
1983-10-01	24
1984-01-01	24
1984-04-01	24
1984-07-01	23
1984-10-01	23
1985-01-01	23
1985-04-01	23
1985-07-01	24
1985-10-01	24
1986-01-01	24
1989-04-01	15
1989-07-01	16
1989-10-01	18
1990-01-01	18
1990-04-01	18
1990-07-01	19
1990-10-01	20
1991-01-01	17
1991-04-01	17
1991-07-01	18
1991-10-01	20
1992-01-01	18
1992-04-01	69
1992-07-01	74
1992-10-01	65
1993-01-01	65
1993-04-01	44
1993-07-01	51
1993-10-01	48
1994-01-01	49
1994-04-01	52
1994-07-01	53
1994-10-01	53
1995-01-01	59
1995-04-01	41
1995-07-01	40
1995-10-01	40
1996-01-01	38
1996-04-01	35
1996-07-01	80
1996-10-01	80
1997-01-01	87
1997-04-01	213
1997-07-01	359
1997-10-01	356
1998-01-01	506
1998-04-01	675
1998-07-01	681
1998-10-01	893
1999-01-01	879
1999-04-01	770
1999-07-01	806
1999-10-01	1201
2000-01-01	1205
2000-04-01	1146
2000-07-01	987
2000-10-01	959
2001-01-01	793
2001-04-01	845
2001-07-01	827
2001-10-01	1070
2002-01-01	1601
2002-04-01	2339
2002-07-01	2348
2002-10-01	4548
2003-01-01	6917
2003-04-01	7121
2003-07-01	7148
2003-10-01	7259
2004-01-01	7705
2004-04-01	8629
2004-07-01	9584
2004-10-01	10366
2005-01-01	10527
2005-04-01	10259
2005-07-01	9671
2005-10-01	10089
2006-01-01	10247
2006-04-01	10728
2006-07-01	11271
2006-10-01	12890
2007-01-01	14545
2007-04-01	16476
2007-07-01	17552
2007-10-01	17483
2008-01-01	17982
2008-04-01	19617
2008-07-01	23263
2008-10-01	23070
2009-01-01	21845
2009-04-01	25683
2009-07-01	25067
2009-10-01	27838
2010-01-01	27490
2010-04-01	31867
2010-07-01	32792
2010-10-01	34578
2011-01-01	39333
2011-04-01	41122
2011-07-01	39737
2011-10-01	39233
2012-01-01	40131
2012-04-01	40918
2012-07-01	44898
2012-10-01	51379
2013-01-01	53121
2013-04-01	63308
2013-07-01	62667
2013-10-01	65997
2014-01-01	66384
2014-04-01	65792
2014-07-01	62191
2014-10-01	61858
2015-01-01	59782
2015-04-01	59623
2015-07-01	59268
2015-10-01	58511
2016-01-01	59565
2016-04-01	59408
2016-07-01	59289
2016-10-01	59838
2017-01-01	59275
2017-04-01	59252
2017-07-01	60631
2017-10-01	61524
2018-01-01	60303
2018-04-01	56718