Quarter	Millions of US Dollars
1991-01-01	713
1991-04-01	713
1991-07-01	713
1991-10-01	713
1992-01-01	713
1992-04-01	713
1992-07-01	813
1992-10-01	813
1993-01-01	813
1993-04-01	813
1993-07-01	1063
1993-10-01	1030
1994-01-01	1062
1994-04-01	1440
1994-07-01	2576
1994-10-01	4465
1995-01-01	4874
1995-04-01	5048
1995-07-01	5657
1995-10-01	6504
1996-01-01	8686
1996-04-01	8987
1996-07-01	10309
1996-10-01	10699
1997-01-01	10185
1997-04-01	10456
1997-07-01	10931
1997-10-01	13577
1998-01-01	17090
1998-04-01	16878
1998-07-01	17478
1998-10-01	18865
1999-01-01	19320
1999-04-01	18569
1999-07-01	19624
1999-10-01	18537
2000-01-01	20272
2000-04-01	20340
2000-07-01	19013
2000-10-01	18848
2001-01-01	17571
2001-04-01	17138
2001-07-01	18597
2001-10-01	18604
2002-01-01	22975
2002-04-01	25863
2002-07-01	25131
2002-10-01	25228
2003-01-01	36114
2003-04-01	38370
2003-07-01	39265
2003-10-01	41366
2004-01-01	39373
2004-04-01	41276
2004-07-01	40819
2004-10-01	41853
2005-01-01	39385
2005-04-01	39348
2005-07-01	38508
2005-10-01	37709
2006-01-01	43859
2006-04-01	50523
2006-07-01	48427
2006-10-01	49490
2007-01-01	58662
2007-04-01	67627
2007-07-01	66768
2007-10-01	63944
2008-01-01	61906
2008-04-01	67270
2008-07-01	57760
2008-10-01	57563
2009-01-01	62389
2009-04-01	80177
2009-07-01	86768
2009-10-01	74192
2010-01-01	67438
2010-04-01	64202
2010-07-01	70504
2010-10-01	69227
2011-01-01	72711
2011-04-01	74003
2011-07-01	69492
2011-10-01	66758
2012-01-01	49309
2012-04-01	34943
2012-07-01	35042
2012-10-01	35532
2013-01-01	34473
2013-04-01	27030
2013-07-01	27142
2013-10-01	27588
2014-01-01	27600
2014-04-01	34576
2014-07-01	35632
2014-10-01	34331
2015-01-01	30530
2015-04-01	31692
2015-07-01	31651
2015-10-01	30781
2016-01-01	32094
2016-04-01	30669
2016-07-01	24864
2016-10-01	23444
2017-01-01	23792
2017-04-01	19659
2017-07-01	13973
2017-10-01	14194
2018-01-01	18279
2018-04-01	17295