Quarter	Millions of US Dollars
1981-10-01	25
1982-01-01	25
1982-04-01	25
1982-07-01	25
1982-10-01	25
1983-01-01	25
1983-04-01	25
1983-07-01	25
1983-10-01	25
1984-01-01	25
1984-04-01	25
1984-07-01	25
1984-10-01	25
1985-01-01	25
1985-04-01	25
1985-07-01	25
1985-10-01	25
1986-01-01	25
1986-04-01	25
1986-07-01	25
1994-01-01	40
1994-04-01	80
1994-07-01	80
1994-10-01	105
1995-01-01	105
1995-04-01	80
1995-07-01	80
1995-10-01	85
1996-01-01	85
1996-04-01	90
1996-07-01	80
1996-10-01	80
1997-01-01	4911
1997-04-01	5021
1997-07-01	5021
1997-10-01	5021
1998-01-01	5026
1998-04-01	5026
1998-07-01	5026
1998-10-01	4435
1999-01-01	4435
1999-04-01	4435
1999-07-01	4435
1999-10-01	4434
2000-01-01	4434
2000-04-01	4434
2000-07-01	4434
2000-10-01	4430
2001-01-01	4430
2001-04-01	4430
2001-07-01	4430
2001-10-01	4430
2002-01-01	5170
2002-04-01	5102
2002-07-01	5102
2002-10-01	4684
2003-01-01	5416
2003-04-01	5416
2003-07-01	5379
2003-10-01	4969
2004-01-01	4969
2004-04-01	5369
2004-07-01	5369
2004-10-01	6254
2005-01-01	6545
2005-04-01	6488
2005-07-01	7235
2005-10-01	7939
2006-01-01	7964
2006-04-01	8010
2006-07-01	8220
2006-10-01	9236
2007-01-01	10664
2007-04-01	10575
2007-07-01	11347
2007-10-01	11450
2008-01-01	10248
2008-04-01	10095
2008-07-01	9994
2008-10-01	9722
2009-01-01	11023
2009-04-01	11191
2009-07-01	12376
2009-10-01	13064
2010-01-01	13607
2010-04-01	14518
2010-07-01	15532
2010-10-01	19112
2011-01-01	20262
2011-04-01	20334
2011-07-01	20335
2011-10-01	20747
2012-01-01	23524
2012-04-01	24832
2012-07-01	26541
2012-10-01	27137
2013-01-01	29202
2013-04-01	31819
2013-07-01	31816
2013-10-01	32467
2014-01-01	33543
2014-04-01	34625
2014-07-01	36300
2014-10-01	40410
2015-01-01	40885
2015-04-01	41566
2015-07-01	43445
2015-10-01	44140
2016-01-01	44507
2016-04-01	43438
2016-07-01	42637
2016-10-01	44547
2017-01-01	44477
2017-04-01	48174
2017-07-01	49302
2017-10-01	50654
2018-01-01	50970
2018-04-01	50868