Quarter	US dollars
1999-03-31	4861
1999-06-30	5059
1999-09-30	4616
1999-12-31	4670
2000-03-31	3516
2000-06-30	3266
2000-09-30	3275
2000-12-31	3030
2001-03-31	4480
2001-06-30	4776
2001-09-30	4238
2001-12-31	3433
2002-03-31	2937
2002-06-30	3751
2002-09-30	3636
2002-12-31	4038
2003-03-31	3927
2003-06-30	4457
2003-09-30	4137
2003-12-31	4657
2004-03-31	4387
2004-06-30	4841
2004-09-30	5066
2004-12-31	5682
2005-03-31	5311
2005-06-30	6753
2005-09-30	5441
2005-12-31	5560
2006-03-31	5526
2006-06-30	6027
2006-09-30	7368
2006-12-31	8503
2007-03-31	7976
2007-06-30	10840
2007-09-30	9264
2007-12-31	9180
2008-03-31	8144
2008-06-30	8486
2008-09-30	7932
2008-12-31	7441
2009-03-31	7762
2009-06-30	6778
2009-09-30	7067
2009-12-31	7120
2010-03-31	7380
2010-06-30	6198
2010-09-30	7338
2010-12-31	7272
2011-03-31	6888
2011-06-30	7393
2011-09-30	6488
2011-12-31	5783
2012-03-31	6754
2012-06-30	6782
2012-09-30	10104
2012-12-31	9420
2013-03-31	9409
2013-06-30	8378
2013-09-30	9225
2013-12-31	10590
2014-03-31	10282
2014-06-30	10073
2014-09-30	9654
2014-12-31	9461
2015-03-31	10673
2015-06-30	10527
2015-09-30	9591
2015-12-31	9438
2016-03-31	10757
2016-06-30	10286
2016-09-30	11588
2016-12-31	9852
2017-03-31	12488
2017-06-30	13087
2017-09-30	13970
2017-12-31	14884
2018-03-31	15654
2018-06-30	12868
2018-09-30	14745
2018-12-31	13203
2019-03-31	16571
2019-06-30	16418
2019-09-30	15117
2019-12-31	13532
2020-03-31	11066
2020-06-30	10912
2020-09-30	10268
2020-12-31	9964
2021-03-31	10072
2021-06-30	8315
2021-09-30	7598
2021-12-31	6383
2022-03-31	9076
2022-06-30	5394
2022-09-30	6675
2022-12-31	6630
2023-03-31	8335
2023-06-30	4299
2023-09-30	5876