Quarter	US dollars
1999-03-31	1930
1999-06-30	1719
1999-09-30	1557
1999-12-31	2454
2000-03-31	1735
2000-06-30	1669
2000-09-30	1752
2000-12-31	1747
2001-03-31	1699
2001-06-30	1665
2001-09-30	1872
2001-12-31	2247
2002-03-31	2120
2002-06-30	2633
2002-09-30	1890
2002-12-31	2043
2003-03-31	2550
2003-06-30	3054
2003-09-30	2515
2003-12-31	2668
2004-03-31	2252
2004-06-30	2496
2004-09-30	2800
2004-12-31	3742
2005-03-31	3086
2005-06-30	3545
2005-09-30	2714
2005-12-31	3041
2006-03-31	3590
2006-06-30	3588
2006-09-30	3612
2006-12-31	4568
2007-03-31	4209
2007-06-30	5039
2007-09-30	4683
2007-12-31	4803
2008-03-31	4888
2008-06-30	5281
2008-09-30	4246
2008-12-31	4033
2009-03-31	4842
2009-06-30	5016
2009-09-30	6266
2009-12-31	5071
2010-03-31	4676
2010-06-30	4663
2010-09-30	4765
2010-12-31	4673
2011-03-31	4320
2011-06-30	4808
2011-09-30	4434
2011-12-31	4841
2012-03-31	4403
2012-06-30	4703
2012-09-30	4105
2012-12-31	4150
2013-03-31	3943
2013-06-30	4482
2013-09-30	2778
2013-12-31	3095
2014-03-31	3048
2014-06-30	1910
2014-09-30	959
2014-12-31	891
2015-03-31	1093
2015-06-30	1322
2015-09-30	2403
2015-12-31	1502
2016-03-31	2030
2016-06-30	2666
2016-09-30	2379
2016-12-31	1799
2017-03-31	2351
2017-06-30	2734
2017-09-30	2503
2017-12-31	2770
2018-03-31	3065
2018-06-30	2927
2018-09-30	3016
2018-12-31	3129
2019-03-31	3291
2019-06-30	2311
2019-09-30	2870
2019-12-31	3291
2020-03-31	3393
2020-06-30	4043
2020-09-30	4261
2020-12-31	2909
2021-03-31	2309
2021-06-30	2702
2021-09-30	2418
2021-12-31	3373
2022-03-31	3022
2022-06-30	3308
2022-09-30	2689
2022-12-31	2944
2023-03-31	2458
2023-06-30	2552
2023-09-30	4318