Quarter	Millions of US Dollars
1977-04-01	50
1977-07-01	50
1977-10-01	50
1978-01-01	50
1978-04-01	50
1978-07-01	50
1978-10-01	50
1979-01-01	50
1979-04-01	50
1979-07-01	50
1979-10-01	50
1980-01-01	50
1980-04-01	50
1980-07-01	50
1980-10-01	50
1981-01-01	50
1981-04-01	50
1981-07-01	50
1981-10-01	50
1982-01-01	50
1982-10-01	25
1983-01-01	45
1983-04-01	45
1983-07-01	45
1983-10-01	45
1984-01-01	46
1984-04-01	106
1984-07-01	122
1984-10-01	159
1985-01-01	179
1985-04-01	220
1985-07-01	300
1985-10-01	323
1986-01-01	360
1986-04-01	394
1986-07-01	419
1986-10-01	438
1987-01-01	478
1987-04-01	475
1987-07-01	546
1987-10-01	657
1988-01-01	814
1988-04-01	754
1988-07-01	744
1988-10-01	800
1989-01-01	752
1989-04-01	698
1989-07-01	774
1989-10-01	764
1990-01-01	711
1990-04-01	736
1990-07-01	807
1990-10-01	824
1991-01-01	781
1991-04-01	676
1991-07-01	670
1991-10-01	715
1992-01-01	667
1992-04-01	709
1992-07-01	670
1992-10-01	591
1993-01-01	540
1993-04-01	580
1993-07-01	584
1993-10-01	550
1994-01-01	595
1994-04-01	618
1994-07-01	630
1994-10-01	516
1995-01-01	531
1995-04-01	441
1995-07-01	406
1995-10-01	397
1996-01-01	387
1996-04-01	486
1996-07-01	308
1996-10-01	487
1997-01-01	470
1997-04-01	475
1997-07-01	465
1997-10-01	455
1998-01-01	449
1998-04-01	446
1998-07-01	457
1998-10-01	478
1999-01-01	463
1999-04-01	457
1999-07-01	372
1999-10-01	1381
2000-01-01	1331
2000-04-01	1391
2000-07-01	1302
2000-10-01	1352
2001-01-01	2174
2001-04-01	2047
2001-07-01	2300
2001-10-01	2569
2002-01-01	2794
2002-04-01	3178
2002-07-01	2833
2002-10-01	3368
2003-01-01	3082
2003-04-01	3600
2003-07-01	3443
2003-10-01	3700
2004-01-01	3502
2004-04-01	4568
2004-07-01	4499
2004-10-01	5117
2005-01-01	5977
2005-04-01	5491
2005-07-01	5150
2005-10-01	5384
2006-01-01	4934
2006-04-01	5571
2006-07-01	5343
2006-10-01	8041
2007-01-01	7416
2007-04-01	8295
2007-07-01	8811
2007-10-01	9545
2008-01-01	10774
2008-04-01	10249
2008-07-01	9503
2008-10-01	10131
2009-01-01	9839
2009-04-01	10618
2009-07-01	10999
2009-10-01	11066
2010-01-01	10366
2010-04-01	9175
2010-07-01	10711
2010-10-01	10572
2011-01-01	9619
2011-04-01	8233
2011-07-01	7349
2011-10-01	7371
2012-01-01	7414
2012-04-01	7055
2012-07-01	7272
2012-10-01	8741
2013-01-01	8997
2013-04-01	8788
2013-07-01	9058
2013-10-01	8783
2014-01-01	8847
2014-04-01	9431
2014-07-01	9323
2014-10-01	8747
2015-01-01	6964
2015-04-01	7552
2015-07-01	8126
2015-10-01	7928
2016-01-01	8695
2016-04-01	8332
2016-07-01	9067
2016-10-01	8023
2017-01-01	7772
2017-04-01	9413
2017-07-01	9006
2017-10-01	9558
2018-01-01	9411
2018-04-01	8953