Quarter	US dollars
1997-09-30	1388
1997-12-31	1604
1998-03-31	2508
1998-06-30	2002
1998-09-30	2273
1998-12-31	2300
1999-03-31	2416
1999-06-30	2856
1999-09-30	3339
1999-12-31	3469
2000-03-31	3453
2000-06-30	3177
2000-09-30	3187
2000-12-31	3171
2001-03-31	3395
2001-06-30	3505
2001-09-30	3480
2001-12-31	3387
2002-03-31	3118
2002-06-30	3468
2002-09-30	3648
2002-12-31	4074
2003-03-31	3952
2003-06-30	4138
2003-09-30	4136
2003-12-31	4739
2004-03-31	4805
2004-06-30	5166
2004-09-30	5465
2004-12-31	7253
2005-03-31	8655
2005-06-30	8180
2005-09-30	7786
2005-12-31	6451
2006-03-31	7079
2006-06-30	8811
2006-09-30	9061
2006-12-31	10854
2007-03-31	11821
2007-06-30	14701
2007-09-30	18395
2007-12-31	17528
2008-03-31	18373
2008-06-30	17944
2008-09-30	17439
2008-12-31	14309
2009-03-31	14824
2009-06-30	16744
2009-09-30	17109
2009-12-31	15373
2010-03-31	14522
2010-06-30	13514
2010-09-30	14127
2010-12-31	13320
2011-03-31	13800
2011-06-30	13698
2011-09-30	12627
2011-12-31	11982
2012-03-31	12235
2012-06-30	12237
2012-09-30	12074
2012-12-31	11946
2013-03-31	11101
2013-06-30	10615
2013-09-30	11397
2013-12-31	11649
2014-03-31	11249
2014-06-30	12706
2014-09-30	10676
2014-12-31	10386
2015-03-31	8984
2015-06-30	9429
2015-09-30	9719
2015-12-31	9888
2016-03-31	9788
2016-06-30	9278
2016-09-30	9016
2016-12-31	9065
2017-03-31	9332
2017-06-30	9620
2017-09-30	9924
2017-12-31	9557
2018-03-31	11280
2018-06-30	8182
2018-09-30	7522
2018-12-31	6570
2019-03-31	6631
2019-06-30	6533
2019-09-30	6525
2019-12-31	6501
2020-03-31	7110
2020-06-30	7057
2020-09-30	6686
2020-12-31	6317
2021-03-31	6950
2021-06-30	7052
2021-09-30	7154
2021-12-31	6521
2022-03-31	5904
2022-06-30	5314
2022-09-30	4897
2022-12-31	4992
2023-03-31	5699
2023-06-30	5991
2023-09-30	5486