Quarter	US dollars
1999-03-31	3336
1999-06-30	2849
1999-09-30	2764
1999-12-31	2987
2000-03-31	3189
2000-06-30	3425
2000-09-30	4268
2000-12-31	5214
2001-03-31	4345
2001-06-30	3663
2001-09-30	3074
2001-12-31	1989
2002-03-31	1738
2002-06-30	1956
2002-09-30	1527
2002-12-31	1618
2003-03-31	1948
2003-06-30	1626
2003-09-30	2260
2003-12-31	3251
2004-03-31	3189
2004-06-30	4188
2004-09-30	4172
2004-12-31	4372
2005-03-31	5758
2005-06-30	6672
2005-09-30	7056
2005-12-31	9081
2006-03-31	10169
2006-06-30	8521
2006-09-30	9160
2006-12-31	9078
2007-03-31	8703
2007-06-30	8060
2007-09-30	8467
2007-12-31	8222
2008-03-31	10097
2008-06-30	8609
2008-09-30	9641
2008-12-31	9435
2009-03-31	8057
2009-06-30	8484
2009-09-30	8144
2009-12-31	8679
2010-03-31	9338
2010-06-30	10689
2010-09-30	10424
2010-12-31	13567
2011-03-31	19898
2011-06-30	21859
2011-09-30	15625
2011-12-31	15268
2012-03-31	15379
2012-06-30	17865
2012-09-30	17715
2012-12-31	20334
2013-03-31	22358
2013-06-30	27113
2013-09-30	27084
2013-12-31	28878
2014-03-31	26998
2014-06-30	29487
2014-09-30	30040
2014-12-31	29166
2015-03-31	27796
2015-06-30	28223
2015-09-30	27883
2015-12-31	27480
2016-03-31	28558
2016-06-30	27193
2016-09-30	26487
2016-12-31	21856
2017-03-31	21539
2017-06-30	20813
2017-09-30	22597
2017-12-31	23949
2018-03-31	24164
2018-06-30	25204
2018-09-30	20670
2018-12-31	18243
2019-03-31	19664
2019-06-30	16807
2019-09-30	15368
2019-12-31	14611
2020-03-31	11751
2020-06-30	11805
2020-09-30	13752
2020-12-31	14955
2021-03-31	16428
2021-06-30	15810
2021-09-30	14763
2021-12-31	15068
2022-03-31	14643
2022-06-30	15195
2022-09-30	14470
2022-12-31	15031
2023-03-31	14916
2023-06-30	15206
2023-09-30	14899