Quarter	US dollars
1999-03-31	5211
1999-06-30	4979
1999-09-30	4730
1999-12-31	4483
2000-03-31	5031
2000-06-30	6083
2000-09-30	9394
2000-12-31	8944
2001-03-31	7920
2001-06-30	6981
2001-09-30	6970
2001-12-31	6474
2002-03-31	5783
2002-06-30	5783
2002-09-30	5585
2002-12-31	5700
2003-03-31	5705
2003-06-30	4484
2003-09-30	4324
2003-12-31	4679
2004-03-31	4915
2004-06-30	3571
2004-09-30	4257
2004-12-31	3508
2005-03-31	4173
2005-06-30	4271
2005-09-30	4509
2005-12-31	3662
2006-03-31	3561
2006-06-30	4148
2006-09-30	4207
2006-12-31	5207
2007-03-31	7352
2007-06-30	8147
2007-09-30	7339
2007-12-31	7300
2008-03-31	8511
2008-06-30	8526
2008-09-30	6860
2008-12-31	7636
2009-03-31	8068
2009-06-30	8108
2009-09-30	7989
2009-12-31	6330
2010-03-31	8556
2010-06-30	8343
2010-09-30	9221
2010-12-31	7239
2011-03-31	10976
2011-06-30	10565
2011-09-30	11017
2011-12-31	10554
2012-03-31	12868
2012-06-30	14670
2012-09-30	15668
2012-12-31	16953
2013-03-31	15339
2013-06-30	14250
2013-09-30	14828
2013-12-31	15317
2014-03-31	16426
2014-06-30	16911
2014-09-30	17051
2014-12-31	16384
2015-03-31	17432
2015-06-30	14786
2015-09-30	14423
2015-12-31	14399
2016-03-31	15038
2016-06-30	13099
2016-09-30	11866
2016-12-31	10997
2017-03-31	12561
2017-06-30	13141
2017-09-30	10904
2017-12-31	11356
2018-03-31	11533
2018-06-30	11410
2018-09-30	10454
2018-12-31	9773
2019-03-31	10162
2019-06-30	9367
2019-09-30	8699
2019-12-31	8856
2020-03-31	10769
2020-06-30	9904
2020-09-30	9754
2020-12-31	10604
2021-03-31	8434
2021-06-30	8717
2021-09-30	7820
2021-12-31	6449
2022-03-31	7040
2022-06-30	6302
2022-09-30	5344
2022-12-31	5114
2023-03-31	4375
2023-06-30	5331
2023-09-30	5738