Quarter	Millions of US Dollars
1992-07-01	200
1992-10-01	200
1993-01-01	350
1993-04-01	350
1993-07-01	350
1993-10-01	350
1994-01-01	550
1994-04-01	550
1994-07-01	550
1994-10-01	750
1995-01-01	950
1995-04-01	950
1995-07-01	950
1995-10-01	950
1996-01-01	950
1996-04-01	950
1996-07-01	950
1996-10-01	950
1997-01-01	950
1997-04-01	950
1997-07-01	950
1997-10-01	950
1998-01-01	950
1998-04-01	1060
1998-07-01	1060
1998-10-01	1060
1999-01-01	1060
1999-04-01	1060
1999-07-01	1060
1999-10-01	2060
2000-01-01	1910
2000-04-01	3060
2000-07-01	3060
2000-10-01	3060
2001-01-01	3060
2001-04-01	3060
2001-07-01	3060
2001-10-01	3060
2002-01-01	3060
2002-04-01	3660
2002-07-01	3460
2002-10-01	3460
2003-01-01	2860
2003-04-01	2860
2003-07-01	2860
2003-10-01	3960
2004-01-01	3760
2004-04-01	3760
2004-07-01	3760
2004-10-01	3560
2005-01-01	5910
2005-04-01	5800
2005-07-01	5800
2005-10-01	6150
2006-01-01	6150
2006-04-01	6294
2006-07-01	9209
2006-10-01	9209
2007-01-01	10046
2007-04-01	10049
2007-07-01	10053
2007-10-01	10059
2008-01-01	10245
2008-04-01	15287
2008-07-01	16926
2008-10-01	16927
2009-01-01	18951
2009-04-01	19870
2009-07-01	19903
2009-10-01	20388
2010-01-01	20060
2010-04-01	19981
2010-07-01	21071
2010-10-01	21202
2011-01-01	21857
2011-04-01	23979
2011-07-01	23918
2011-10-01	23906
2012-01-01	20284
2012-04-01	20284
2012-07-01	20319
2012-10-01	19986
2013-01-01	19386
2013-04-01	19179
2013-07-01	20085
2013-10-01	19421
2014-01-01	19421
2014-04-01	18267
2014-07-01	17537
2014-10-01	17887
2015-01-01	16522
2015-04-01	16400
2015-07-01	16350
2015-10-01	16329
2016-01-01	16062
2016-04-01	13388
2016-07-01	13311
2016-10-01	13671
2017-01-01	9224
2017-04-01	9276
2017-07-01	9683
2017-10-01	9693
2018-01-01	8934
2018-04-01	16100