Quarter	US dollars
1999-03-31	4116
1999-06-30	3758
1999-09-30	4378
1999-12-31	3909
2000-03-31	3990
2000-06-30	4633
2000-09-30	4416
2000-12-31	4627
2001-03-31	4422
2001-06-30	4078
2001-09-30	5129
2001-12-31	4782
2002-03-31	6017
2002-06-30	7006
2002-09-30	7563
2002-12-31	8353
2003-03-31	8468
2003-06-30	8330
2003-09-30	9192
2003-12-31	9371
2004-03-31	8893
2004-06-30	7776
2004-09-30	8161
2004-12-31	8935
2005-03-31	10778
2005-06-30	10022
2005-09-30	11143
2005-12-31	11581
2006-03-31	8323
2006-06-30	9041
2006-09-30	7395
2006-12-31	8078
2007-03-31	8350
2007-06-30	7673
2007-09-30	10506
2007-12-31	10168
2008-03-31	12436
2008-06-30	12510
2008-09-30	11171
2008-12-31	7902
2009-03-31	9948
2009-06-30	9131
2009-09-30	8588
2009-12-31	8245
2010-03-31	7178
2010-06-30	5735
2010-09-30	6817
2010-12-31	4991
2011-03-31	5843
2011-06-30	7267
2011-09-30	7442
2011-12-31	7293
2012-03-31	6638
2012-06-30	7443
2012-09-30	7606
2012-12-31	7518
2013-03-31	6479
2013-06-30	6033
2013-09-30	6042
2013-12-31	5775
2014-03-31	5684
2014-06-30	5751
2014-09-30	4885
2014-12-31	4968
2015-03-31	4451
2015-06-30	4068
2015-09-30	4138
2015-12-31	3961
2016-03-31	6415
2016-06-30	6320
2016-09-30	5571
2016-12-31	3986
2017-03-31	3530
2017-06-30	3346
2017-09-30	3017
2017-12-31	2806
2018-03-31	2762
2018-06-30	2632
2018-09-30	1926
2018-12-31	1583
2019-03-31	1748
2019-06-30	2047
2019-09-30	1881
2019-12-31	2208
2020-03-31	2357
2020-06-30	1875
2020-09-30	2083
2020-12-31	1510
2021-03-31	1155
2021-06-30	1149
2021-09-30	735
2021-12-31	1114
2022-03-31	775
2022-06-30	1377
2022-09-30	830
2022-12-31	1043
2023-03-31	977
2023-06-30	1085
2023-09-30	934