Quarter	US dollars
1999-03-31	4675
1999-06-30	5028
1999-09-30	4824
1999-12-31	3351
2000-03-31	5655
2000-06-30	6401
2000-09-30	6245
2000-12-31	5957
2001-03-31	6013
2001-06-30	5940
2001-09-30	5024
2001-12-31	4531
2002-03-31	4859
2002-06-30	4312
2002-09-30	3206
2002-12-31	2936
2003-03-31	3098
2003-06-30	2397
2003-09-30	2692
2003-12-31	3294
2004-03-31	7294
2004-06-30	5322
2004-09-30	6672
2004-12-31	8008
2005-03-31	9763
2005-06-30	8137
2005-09-30	7539
2005-12-31	2809
2006-03-31	5435
2006-06-30	5540
2006-09-30	5281
2006-12-31	7821
2007-03-31	10868
2007-06-30	11571
2007-09-30	12896
2007-12-31	12366
2008-03-31	9850
2008-06-30	9048
2008-09-30	5647
2008-12-31	1829
2009-03-31	4126
2009-06-30	3418
2009-09-30	3381
2009-12-31	3031
2010-03-31	4316
2010-06-30	4159
2010-09-30	3138
2010-12-31	3850
2011-03-31	4101
2011-06-30	4947
2011-09-30	5662
2011-12-31	4428
2012-03-31	3006
2012-06-30	4087
2012-09-30	3349
2012-12-31	3311
2013-03-31	2948
2013-06-30	3021
2013-09-30	3423
2013-12-31	2413
2014-03-31	3312
2014-06-30	5386
2014-09-30	5179
2014-12-31	4317
2015-03-31	3990
2015-06-30	4351
2015-09-30	2277
2015-12-31	2392
2016-03-31	2241
2016-06-30	1392
2016-09-30	1313
2016-12-31	1288
2017-03-31	1309
2017-06-30	826
2017-09-30	812
2017-12-31	690
2018-03-31	1212
2018-06-30	864
2018-09-30	814
2018-12-31	736
2019-03-31	975
2019-06-30	1416
2019-09-30	1073
2019-12-31	957
2020-03-31	2068
2020-06-30	1200
2020-09-30	1602
2020-12-31	1219
2021-03-31	1405
2021-06-30	1199
2021-09-30	948
2021-12-31	777
2022-03-31	1505
2022-06-30	1434
2022-09-30	1462
2022-12-31	1053
2023-03-31	1309
2023-06-30	1043
2023-09-30	879