Quarter	Millions of US Dollars
1978-07-01	62
1978-10-01	62
1979-01-01	61
1979-04-01	61
1979-07-01	61
1979-10-01	62
1980-01-01	61
1980-04-01	62
1980-07-01	62
1980-10-01	62
1981-01-01	61
1981-04-01	61
1981-07-01	60
1981-10-01	61
1982-01-01	60
1982-04-01	60
1982-07-01	59
1982-10-01	60
1983-01-01	59
1983-04-01	59
1983-07-01	34
1983-10-01	34
1984-01-01	34
1984-04-01	34
1984-07-01	83
1984-10-01	83
1985-01-01	83
1985-04-01	83
1985-07-01	84
1985-10-01	85
1986-01-01	84
1986-04-01	84
1986-07-01	50
1986-10-01	50
1987-01-01	87
1987-04-01	80
1987-07-01	85
1987-10-01	50
1988-01-01	50
1988-04-01	50
1988-07-01	50
1988-10-01	50
1989-01-01	50
1989-04-01	50
1989-07-01	50
1989-10-01	78
1990-01-01	50
1990-04-01	50
1990-07-01	50
1990-10-01	50
1991-01-01	50
1991-04-01	50
1991-07-01	50
1991-10-01	50
1992-01-01	50
1992-04-01	50
2002-01-01	450
2002-04-01	450
2002-07-01	750
2002-10-01	750
2003-01-01	750
2003-04-01	750
2003-07-01	750
2003-10-01	950
2004-01-01	950
2004-04-01	950
2004-07-01	950
2004-10-01	1450
2005-01-01	1000
2005-04-01	1500
2005-07-01	2189
2005-10-01	2243
2006-01-01	2790
2006-04-01	2635
2006-07-01	2204
2006-10-01	2454
2007-01-01	2453
2007-04-01	2675
2007-07-01	2317
2007-10-01	2237
2008-01-01	2656
2008-04-01	2607
2008-07-01	2514
2008-10-01	2191
2009-01-01	2126
2009-04-01	2169
2009-07-01	2194
2009-10-01	1688
2010-01-01	1665
2010-04-01	1119
2010-07-01	1589
2010-10-01	1580
2011-01-01	1797
2011-04-01	1230
2011-07-01	1436
2011-10-01	1341
2012-01-01	1367
2012-04-01	1431
2012-07-01	1331
2012-10-01	1275
2013-01-01	1070
2013-04-01	1057
2013-07-01	1069
2013-10-01	1067
2014-01-01	1070
2014-04-01	1080
2014-07-01	1782
2014-10-01	1743
2015-01-01	1710
2015-04-01	2562
2015-07-01	2484
2015-10-01	2093
2016-01-01	2109
2016-04-01	2676
2016-07-01	2478
2016-10-01	2651
2017-01-01	7977
2017-04-01	9373
2017-07-01	9509
2017-10-01	9614
2018-01-01	9641
2018-04-01	9602