Quarter	Millions of US Dollars
1989-07-01	107
1989-10-01	160
1990-01-01	156
1990-04-01	159
1990-07-01	171
1990-10-01	178
1991-01-01	159
1991-04-01	154
1991-07-01	166
1991-10-01	180
1992-01-01	167
1992-04-01	179
1992-07-01	192
1992-10-01	172
1993-01-01	176
1993-04-01	175
1993-07-01	185
1993-10-01	173
1994-01-01	182
1994-04-01	191
1994-07-01	5313
1994-10-01	5312
1995-01-01	5336
1995-04-01	5338
1995-07-01	5324
1995-10-01	5320
1996-01-01	5314
1996-04-01	5308
1996-07-01	5176
1996-10-01	5174
1997-01-01	5171
1997-04-01	5175
1997-07-01	5204
1997-10-01	5201
1998-01-01	5201
1998-04-01	5199
1998-07-01	5201
1998-10-01	5210
1999-01-01	5208
1999-04-01	5259
1999-07-01	5269
1999-10-01	5209
2000-01-01	5208
2000-04-01	5208
2000-07-01	5204
2000-10-01	5208
2001-01-01	5206
2001-04-01	5204
2001-07-01	5192
2001-10-01	5412
2002-01-01	5051
2002-04-01	5065
2002-07-01	4985
2002-10-01	4185
2003-01-01	4179
2003-04-01	4238
2003-07-01	4212
2003-10-01	4319
2004-01-01	4266
2004-04-01	4259
2004-07-01	3608
2004-10-01	3741
2005-01-01	2580
2005-04-01	2486
2005-07-01	2026
2005-10-01	1997
2006-01-01	2061
2006-04-01	2137
2006-07-01	2131
2006-10-01	2426
2007-01-01	2115
2007-04-01	2137
2007-07-01	2216
2007-10-01	2280
2008-01-01	2407
2008-04-01	2402
2008-07-01	2470
2008-10-01	2418
2009-01-01	2339
2009-04-01	2409
2009-07-01	2425
2009-10-01	2369
2010-01-01	2251
2010-04-01	2097
2010-07-01	2000
2010-10-01	1969
2011-01-01	2061
2011-04-01	2087
2011-07-01	1985
2011-10-01	1796
2012-01-01	1837
2012-04-01	1762
2012-07-01	3025
2012-10-01	3226
2013-01-01	2105
2013-04-01	2136
2013-07-01	2184
2013-10-01	3457
2014-01-01	3457
2014-04-01	3431
2014-07-01	4944
2014-10-01	4790
2015-01-01	7131
2015-04-01	7416
2015-07-01	7353
2015-10-01	7282
2016-01-01	9896
2016-04-01	9599
2016-07-01	10269
2016-10-01	9803
2017-01-01	9946
2017-04-01	10626
2017-07-01	9877
2017-10-01	10112
2018-01-01	10388
2018-04-01	10297