Quarter	Millions of US Dollars
1987-04-01	2448
1987-07-01	2637
1987-10-01	4827
1988-01-01	4817
1988-04-01	4603
1988-07-01	4518
1988-10-01	4597
1989-01-01	3900
1989-04-01	4886
1989-07-01	5374
1989-10-01	7329
1990-01-01	5576
1990-04-01	7608
1990-07-01	12080
1990-10-01	12796
1991-01-01	12167
1991-04-01	11297
1991-07-01	13261
1991-10-01	13382
1992-01-01	14332
1992-04-01	12687
1992-07-01	13990
1992-10-01	15594
1993-01-01	16659
1993-04-01	20455
1993-07-01	25855
1993-10-01	24452
1994-01-01	27200
1994-04-01	29321
1994-07-01	22957
1994-10-01	27713
1995-01-01	30996
1995-04-01	34187
1995-07-01	25244
1995-10-01	33776
1996-01-01	35874
1996-04-01	43851
1996-07-01	46899
1996-10-01	49550
1997-01-01	52394
1997-04-01	49526
1997-07-01	43579
1997-10-01	43549
1998-01-01	50465
1998-04-01	50173
1998-07-01	55450
1998-10-01	55831
1999-01-01	53114
1999-04-01	51710
1999-07-01	49445
1999-10-01	47964
2000-01-01	53323
2000-04-01	48894
2000-07-01	46022
2000-10-01	38260
2001-01-01	40416
2001-04-01	35352
2001-07-01	34389
2001-10-01	31683
2002-01-01	33479
2002-04-01	30837
2002-07-01	27144
2002-10-01	25261
2003-01-01	26001
2003-04-01	24732
2003-07-01	25501
2003-10-01	23994
2004-01-01	27472
2004-04-01	25113
2004-07-01	23868
2004-10-01	24618
2005-01-01	24738
2005-04-01	23335
2005-07-01	22487
2005-10-01	22979
2006-01-01	24261
2006-04-01	22819
2006-07-01	21423
2006-10-01	22271
2007-01-01	21223
2007-04-01	19257
2007-07-01	21081
2007-10-01	20753
2008-01-01	22861
2008-04-01	22807
2008-07-01	22203
2008-10-01	21170
2009-01-01	21516
2009-04-01	21065
2009-07-01	20988
2009-10-01	20521
2010-01-01	24128
2010-04-01	21973
2010-07-01	22563
2010-10-01	23749
2011-01-01	25486
2011-04-01	23622
2011-07-01	23379
2011-10-01	24456
2012-01-01	29642
2012-04-01	31253
2012-07-01	33890
2012-10-01	35385
2013-01-01	38618
2013-04-01	38794
2013-07-01	40163
2013-10-01	40357
2014-01-01	42691
2014-04-01	43721
2014-07-01	43724
2014-10-01	41410
2015-01-01	45526
2015-04-01	45091
2015-07-01	40805
2015-10-01	41070
2016-01-01	46465
2016-04-01	46634
2016-07-01	49540
2016-10-01	45775
2017-01-01	56839
2017-04-01	55343
2017-07-01	56633
2017-10-01	57772
2018-01-01	61703