Quarter	Millions of US Dollars
1987-04-01	3596
1987-07-01	3699
1987-10-01	4571
1988-01-01	5348
1988-04-01	5827
1988-07-01	6685
1988-10-01	6603
1989-01-01	7541
1989-04-01	9170
1989-07-01	9174
1989-10-01	8516
1990-01-01	8055
1990-04-01	7739
1990-07-01	7503
1990-10-01	6958
1991-01-01	7630
1991-04-01	10815
1991-07-01	10808
1991-10-01	13502
1992-01-01	16192
1992-04-01	19078
1992-07-01	20600
1992-10-01	21706
1993-01-01	23376
1993-04-01	25079
1993-07-01	25449
1993-10-01	27126
1994-01-01	28553
1994-04-01	27067
1994-07-01	27668
1994-10-01	30345
1995-01-01	31212
1995-04-01	30532
1995-07-01	30215
1995-10-01	31775
1996-01-01	31053
1996-04-01	30410
1996-07-01	32627
1996-10-01	36202
1997-01-01	37196
1997-04-01	35764
1997-07-01	33859
1997-10-01	31550
1998-01-01	31997
1998-04-01	30344
1998-07-01	31053
1998-10-01	32349
1999-01-01	32291
1999-04-01	32982
1999-07-01	36690
1999-10-01	39698
2000-01-01	44466
2000-04-01	44586
2000-07-01	46247
2000-10-01	44721
2001-01-01	50018
2001-04-01	48039
2001-07-01	51750
2001-10-01	53009
2002-01-01	57258
2002-04-01	61424
2002-07-01	61848
2002-10-01	63718
2003-01-01	68175
2003-04-01	70686
2003-07-01	74953
2003-10-01	76148
2004-01-01	81564
2004-04-01	81215
2004-07-01	83299
2004-10-01	89671
2005-01-01	93136
2005-04-01	94853
2005-07-01	92776
2005-10-01	95681
2006-01-01	98836
2006-04-01	101371
2006-07-01	101520
2006-10-01	103880
2007-01-01	101582
2007-04-01	105712
2007-07-01	105483
2007-10-01	108508
2008-01-01	117498
2008-04-01	119970
2008-07-01	113912
2008-10-01	113778
2009-01-01	112183
2009-04-01	118954
2009-07-01	121593
2009-10-01	124184
2010-01-01	128453
2010-04-01	130091
2010-07-01	134935
2010-10-01	148690
2011-01-01	147672
2011-04-01	156365
2011-07-01	148540
2011-10-01	153315
2012-01-01	157185
2012-04-01	161858
2012-07-01	166207
2012-10-01	169872
2013-01-01	167158
2013-04-01	170116
2013-07-01	173106
2013-10-01	174706
2014-01-01	171309
2014-04-01	180102
2014-07-01	175277
2014-10-01	171826
2015-01-01	172671
2015-04-01	179440
2015-07-01	165855
2015-10-01	169416
2016-01-01	170177
2016-04-01	174248
2016-07-01	176247
2016-10-01	172882
2017-01-01	181568
2017-04-01	184658
2017-07-01	182845
2017-10-01	190070
2018-01-01	188340