Quarter	US dollars
1999-03-31	13953
1999-06-30	14652
1999-09-30	14002
1999-12-31	10052
2000-03-31	9975
2000-06-30	12632
2000-09-30	15774
2000-12-31	12178
2001-03-31	11450
2001-06-30	11641
2001-09-30	9765
2001-12-31	9414
2002-03-31	11404
2002-06-30	12889
2002-09-30	15727
2002-12-31	14292
2003-03-31	18527
2003-06-30	22610
2003-09-30	25625
2003-12-31	25900
2004-03-31	29275
2004-06-30	31510
2004-09-30	30272
2004-12-31	36156
2005-03-31	36384
2005-06-30	34151
2005-09-30	30593
2005-12-31	31358
2006-03-31	27763
2006-06-30	27585
2006-09-30	33967
2006-12-31	30004
2007-03-31	36954
2007-06-30	40094
2007-09-30	48999
2007-12-31	48669
2008-03-31	40476
2008-06-30	40124
2008-09-30	28701
2008-12-31	41734
2009-03-31	38283
2009-06-30	31265
2009-09-30	34192
2009-12-31	23988
2010-03-31	23352
2010-06-30	20197
2010-09-30	21098
2010-12-31	15944
2011-03-31	17962
2011-06-30	18900
2011-09-30	19445
2011-12-31	16708
2012-03-31	21306
2012-06-30	26187
2012-09-30	17848
2012-12-31	16960
2013-03-31	22137
2013-06-30	21603
2013-09-30	27594
2013-12-31	28701
2014-03-31	28772
2014-06-30	19572
2014-09-30	14189
2014-12-31	12943
2015-03-31	16338
2015-06-30	12686
2015-09-30	10934
2015-12-31	11214
2016-03-31	11965
2016-06-30	11208
2016-09-30	11342
2016-12-31	11528
2017-03-31	10738
2017-06-30	8718
2017-09-30	9243
2017-12-31	8561
2018-03-31	10697
2018-06-30	8298
2018-09-30	8697
2018-12-31	5308
2019-03-31	7782
2019-06-30	5633
2019-09-30	6564
2019-12-31	4547
2020-03-31	4800
2020-06-30	5093
2020-09-30	5262
2020-12-31	4997
2021-03-31	3723
2021-06-30	3610
2021-09-30	3221
2021-12-31	3842
2022-03-31	3515
2022-06-30	3463
2022-09-30	3551
2022-12-31	3767
2023-03-31	1785
2023-06-30	2159
2023-09-30	2090