Quarter	US dollars
1999-03-31	3688
1999-06-30	3431
1999-09-30	3813
1999-12-31	3818
2000-03-31	4102
2000-06-30	3407
2000-09-30	3587
2000-12-31	4015
2001-03-31	5401
2001-06-30	4292
2001-09-30	8567
2001-12-31	5612
2002-03-31	6859
2002-06-30	6420
2002-09-30	6007
2002-12-31	5605
2003-03-31	6201
2003-06-30	8475
2003-09-30	9107
2003-12-31	6966
2004-03-31	7534
2004-06-30	6851
2004-09-30	8273
2004-12-31	8719
2005-03-31	7289
2005-06-30	7889
2005-09-30	9940
2005-12-31	10704
2006-03-31	14041
2006-06-30	14331
2006-09-30	13984
2006-12-31	24079
2007-03-31	13429
2007-06-30	14112
2007-09-30	14453
2007-12-31	17444
2008-03-31	11709
2008-06-30	11603
2008-09-30	13726
2008-12-31	12402
2009-03-31	9594
2009-06-30	10572
2009-09-30	10387
2009-12-31	7516
2010-03-31	9699
2010-06-30	8780
2010-09-30	11821
2010-12-31	11219
2011-03-31	17330
2011-06-30	16925
2011-09-30	20040
2011-12-31	18196
2012-03-31	20617
2012-06-30	20667
2012-09-30	17574
2012-12-31	17256
2013-03-31	22247
2013-06-30	21502
2013-09-30	20653
2013-12-31	21130
2014-03-31	23559
2014-06-30	28933
2014-09-30	30705
2014-12-31	26349
2015-03-31	28674
2015-06-30	29877
2015-09-30	32506
2015-12-31	30722
2016-03-31	33056
2016-06-30	39457
2016-09-30	31332
2016-12-31	30966
2017-03-31	33408
2017-06-30	31758
2017-09-30	34409
2017-12-31	40515
2018-03-31	42766
2018-06-30	42160
2018-09-30	37568
2018-12-31	50443
2019-03-31	39963
2019-06-30	46589
2019-09-30	46004
2019-12-31	51986
2020-03-31	57757
2020-06-30	49891
2020-09-30	52558
2020-12-31	53323
2021-03-31	55633
2021-06-30	60014
2021-09-30	62728
2021-12-31	62747
2022-03-31	59986
2022-06-30	61191
2022-09-30	57011
2022-12-31	60123
2023-03-31	66006
2023-06-30	63988
2023-09-30	61838