Quarter	Millions of US Dollars
1980-07-01	25
1980-10-01	25
1981-01-01	25
1981-04-01	25
1981-07-01	25
1981-10-01	25
1982-01-01	65
1982-04-01	84
1982-07-01	81
1982-10-01	89
1983-01-01	88
1983-04-01	128
1983-07-01	150
1983-10-01	151
1984-01-01	154
1984-04-01	149
1984-07-01	147
1984-10-01	224
1985-01-01	344
1985-04-01	475
1985-07-01	838
1985-10-01	1098
1986-01-01	1545
1986-04-01	2083
1986-07-01	2521
1986-10-01	2624
1987-01-01	3014
1987-04-01	3198
1987-07-01	3431
1987-10-01	4335
1988-01-01	4500
1988-04-01	4402
1988-07-01	4602
1988-10-01	5053
1989-01-01	4830
1989-04-01	4703
1989-07-01	4822
1989-10-01	4771
1990-01-01	4496
1990-04-01	4602
1990-07-01	4891
1990-10-01	4975
1991-01-01	4795
1991-04-01	4826
1991-07-01	5144
1991-10-01	5430
1992-01-01	5016
1992-04-01	5291
1992-07-01	5743
1992-10-01	5533
1993-01-01	5584
1993-04-01	6306
1993-07-01	7664
1993-10-01	7688
1994-01-01	9524
1994-04-01	10164
1994-07-01	11429
1994-10-01	11804
1995-01-01	12631
1995-04-01	12604
1995-07-01	12188
1995-10-01	11790
1996-01-01	11482
1996-04-01	11225
1996-07-01	12482
1996-10-01	12545
1997-01-01	12871
1997-04-01	14738
1997-07-01	14434
1997-10-01	14498
1998-01-01	14396
1998-04-01	13450
1998-07-01	12725
1998-10-01	14018
1999-01-01	13345
1999-04-01	13490
1999-07-01	13571
1999-10-01	13583
2000-01-01	13241
2000-04-01	13202
2000-07-01	12831
2000-10-01	12688
2001-01-01	12297
2001-04-01	13653
2001-07-01	12392
2001-10-01	12351
2002-01-01	13184
2002-04-01	12331
2002-07-01	11878
2002-10-01	11004
2003-01-01	10727
2003-04-01	10737
2003-07-01	10734
2003-10-01	11841
2004-01-01	10996
2004-04-01	10419
2004-07-01	10953
2004-10-01	14129
2005-01-01	13842
2005-04-01	13408
2005-07-01	14612
2005-10-01	15531
2006-01-01	15346
2006-04-01	14708
2006-07-01	14181
2006-10-01	14117
2007-01-01	14921
2007-04-01	16989
2007-07-01	18279
2007-10-01	18671
2008-01-01	19517
2008-04-01	19532
2008-07-01	21589
2008-10-01	20013
2009-01-01	19908
2009-04-01	19542
2009-07-01	20505
2009-10-01	21347
2010-01-01	21278
2010-04-01	20788
2010-07-01	19878
2010-10-01	21961
2011-01-01	22616
2011-04-01	24489
2011-07-01	25011
2011-10-01	25702
2012-01-01	26804
2012-04-01	34406
2012-07-01	36911
2012-10-01	39261
2013-01-01	41263
2013-04-01	43630
2013-07-01	45285
2013-10-01	49890
2014-01-01	51105
2014-04-01	54457
2014-07-01	56954
2014-10-01	84329
2015-01-01	83694
2015-04-01	86331
2015-07-01	92262
2015-10-01	100153
2016-01-01	104806
2016-04-01	120301
2016-07-01	132964
2016-10-01	140112
2017-01-01	152429
2017-04-01	155100
2017-07-01	167283
2017-10-01	192671
2018-01-01	203695
2018-04-01	202894