Quarter	US dollars
1999-09-30	3272
1999-12-31	3547
2000-03-31	2292
2000-06-30	2563
2000-09-30	3391
2000-12-31	4116
2001-03-31	4960
2001-06-30	4567
2001-09-30	5196
2001-12-31	7850
2002-03-31	3228
2002-06-30	5667
2002-09-30	6078
2002-12-31	8706
2003-03-31	7618
2003-06-30	9091
2003-09-30	10934
2003-12-31	10958
2004-03-31	12384
2004-06-30	9431
2004-09-30	10201
2004-12-31	13649
2005-03-31	13029
2005-06-30	13566
2005-09-30	12465
2005-12-31	12802
2006-03-31	14145
2006-06-30	15585
2006-09-30	15226
2006-12-31	14609
2007-03-31	15020
2007-06-30	18007
2007-09-30	22041
2007-12-31	33304
2008-03-31	51854
2008-06-30	43842
2008-09-30	50022
2008-12-31	68193
2009-03-31	53983
2009-06-30	37094
2009-09-30	37251
2009-12-31	30392
2010-03-31	28274
2010-06-30	34018
2010-09-30	37223
2010-12-31	40637
2011-03-31	26332
2011-06-30	29967
2011-09-30	42481
2011-12-31	31254
2012-03-31	27249
2012-06-30	27669
2012-09-30	25092
2012-12-31	20980
2013-03-31	22053
2013-06-30	20519
2013-09-30	19107
2013-12-31	18092
2014-03-31	15774
2014-06-30	18366
2014-09-30	18665
2014-12-31	20353
2015-03-31	21449
2015-06-30	17948
2015-09-30	20714
2015-12-31	17194
2016-03-31	17921
2016-06-30	20454
2016-09-30	16554
2016-12-31	21351
2017-03-31	13371
2017-06-30	13171
2017-09-30	13896
2017-12-31	13113
2018-03-31	14914
2018-06-30	11388
2018-09-30	14847
2018-12-31	15698
2019-03-31	13360
2019-06-30	15457
2019-09-30	19575
2019-12-31	17034
2020-03-31	30934
2020-06-30	22325
2020-09-30	21551
2020-12-31	26663
2021-03-31	21370
2021-06-30	20675
2021-09-30	18600
2021-12-31	17338
2022-03-31	19532
2022-06-30	24701
2022-09-30	29574
2022-12-31	21565
2023-03-31	15792
2023-06-30	19857
2023-09-30	19383