Quarter	Millions of US Dollars
1994-04-01	40
1994-07-01	40
1994-10-01	40
1995-01-01	40
1995-04-01	40
1995-07-01	40
1995-10-01	40
1996-01-01	40
1996-04-01	40
1996-07-01	40
1996-10-01	40
1997-01-01	40
1997-04-01	150
1997-07-01	150
1997-10-01	150
1998-01-01	150
1998-04-01	150
1998-07-01	150
1998-10-01	150
1999-01-01	150
1999-04-01	150
1999-07-01	150
1999-10-01	150
2000-01-01	150
2000-04-01	150
2000-07-01	150
2000-10-01	150
2001-01-01	150
2001-04-01	150
2001-07-01	150
2001-10-01	150
2002-01-01	150
2002-04-01	100
2002-07-01	100
2002-10-01	100
2003-01-01	100
2003-04-01	100
2003-07-01	100
2003-10-01	100
2004-01-01	100
2005-10-01	220
2006-01-01	225
2006-04-01	231
2006-07-01	232
2006-10-01	236
2007-01-01	237
2007-04-01	238
2007-07-01	409
2007-10-01	431
2008-01-01	454
2008-04-01	433
2008-07-01	432
2008-10-01	419
2009-01-01	519
2009-04-01	559
2009-07-01	612
2009-10-01	812
2010-01-01	919
2010-04-01	1116
2010-07-01	1259
2010-10-01	1307
2011-01-01	1643
2011-04-01	1645
2011-07-01	1640
2011-10-01	1978
2012-01-01	2709
2012-04-01	3701
2012-07-01	4239
2012-10-01	4254
2013-01-01	5598
2013-04-01	7644
2013-07-01	7629
2013-10-01	8063
2014-01-01	8856
2014-04-01	9345
2014-07-01	10250
2014-10-01	10960
2015-01-01	11094
2015-04-01	10791
2015-07-01	10735
2015-10-01	10625
2016-01-01	10673
2016-04-01	10815
2016-07-01	10549
2016-10-01	10571
2017-01-01	10427
2017-04-01	13974
2017-07-01	15058
2017-10-01	15070
2018-01-01	15644
2018-04-01	16384