Quarter	Millions of US Dollars
1972-10-01	10
1973-01-01	24
1973-04-01	24
1973-07-01	24
1973-10-01	24
1974-01-01	24
1974-04-01	24
1974-07-01	24
1974-10-01	24
1975-01-01	24
1975-04-01	24
1975-07-01	24
1975-10-01	24
1976-01-01	24
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	24
1978-01-01	24
1978-04-01	24
1978-07-01	24
1978-10-01	24
1979-01-01	24
1979-04-01	24
1979-07-01	24
1979-10-01	14
1980-01-01	14
1980-04-01	14
1980-07-01	14
1980-10-01	14
1981-01-01	14
1981-04-01	14
1981-07-01	14
1981-10-01	14
1982-01-01	14
1982-04-01	14
1982-07-01	14
1982-10-01	14
1983-01-01	14
1983-04-01	14
1983-07-01	14
1983-10-01	14
1984-01-01	14
1984-04-01	14
1984-07-01	14
1984-10-01	14
1985-01-01	14
1985-04-01	14
1985-07-01	14
1985-10-01	14
1986-01-01	14
1986-04-01	14
1986-07-01	14
1986-10-01	14
1987-01-01	14
1987-04-01	14
1987-07-01	14
1987-10-01	14
1997-07-01	200
1997-10-01	200
1998-01-01	200
1998-04-01	450
1998-07-01	450
1998-10-01	450
1999-01-01	450
1999-04-01	450
1999-07-01	450
1999-10-01	450
2000-01-01	641
2000-04-01	641
2000-07-01	850
2000-10-01	861
2001-01-01	1006
2001-04-01	1393
2001-07-01	1417
2001-10-01	1655
2002-01-01	1652
2002-04-01	1999
2002-07-01	1795
2002-10-01	1818
2003-01-01	1616
2003-04-01	1625
2003-07-01	1629
2003-10-01	1646
2004-01-01	1883
2004-04-01	2006
2004-07-01	2046
2004-10-01	2299
2005-01-01	2263
2005-04-01	2265
2005-07-01	2262
2005-10-01	2499
2006-01-01	2766
2006-04-01	2799
2006-07-01	2796
2006-10-01	2824
2007-01-01	3182
2007-04-01	3193
2007-07-01	3005
2007-10-01	3185
2008-01-01	3245
2008-04-01	3592
2008-07-01	3512
2008-10-01	3490
2009-01-01	3191
2009-04-01	3220
2009-07-01	3238
2009-10-01	3229
2010-01-01	3197
2010-04-01	3154
2010-07-01	3203
2010-10-01	3193
2011-01-01	3622
2011-04-01	3231
2011-07-01	3198
2011-10-01	3178
2012-01-01	3192
2012-04-01	3166
2012-07-01	2919
2012-10-01	2923
2013-01-01	2917
2013-04-01	2921
2013-07-01	2928
2013-10-01	2932
2014-01-01	2932
2014-04-01	2930
2014-07-01	3714
2014-10-01	3525
2015-01-01	3525
2015-04-01	3225
2015-07-01	5225
2015-10-01	5225
2016-01-01	5225
2016-04-01	5225
2016-07-01	5968
2016-10-01	5968
2017-01-01	5968
2017-04-01	5543
2017-07-01	6412
2017-10-01	6412
2018-01-01	6412
2018-04-01	6412