Quarter	US dollars
1999-03-31	6258
1999-06-30	6148
1999-09-30	7490
1999-12-31	7011
2000-03-31	6780
2000-06-30	6480
2000-09-30	6058
2000-12-31	6098
2001-03-31	6326
2001-06-30	6424
2001-09-30	6702
2001-12-31	6954
2002-03-31	7417
2002-06-30	8294
2002-09-30	8257
2002-12-31	7447
2003-03-31	9994
2003-06-30	8268
2003-09-30	9322
2003-12-31	9654
2004-03-31	10982
2004-06-30	10151
2004-09-30	12196
2004-12-31	12344
2005-03-31	12936
2005-06-30	12939
2005-09-30	12927
2005-12-31	15937
2006-03-31	15163
2006-06-30	14024
2006-09-30	15998
2006-12-31	18434
2007-03-31	18366
2007-06-30	19425
2007-09-30	24119
2007-12-31	24290
2008-03-31	21241
2008-06-30	21675
2008-09-30	27534
2008-12-31	19398
2009-03-31	15494
2009-06-30	19482
2009-09-30	15791
2009-12-31	16141
2010-03-31	18628
2010-06-30	22020
2010-09-30	24421
2010-12-31	20044
2011-03-31	26205
2011-06-30	23861
2011-09-30	23639
2011-12-31	33732
2012-03-31	24120
2012-06-30	26078
2012-09-30	24012
2012-12-31	22103
2013-03-31	20687
2013-06-30	20624
2013-09-30	21837
2013-12-31	20636
2014-03-31	20066
2014-06-30	23158
2014-09-30	24543
2014-12-31	22668
2015-03-31	22622
2015-06-30	22403
2015-09-30	28276
2015-12-31	24533
2016-03-31	23889
2016-06-30	21902
2016-09-30	27348
2016-12-31	22843
2017-03-31	28424
2017-06-30	29512
2017-09-30	30964
2017-12-31	28902
2018-03-31	33893
2018-06-30	26170
2018-09-30	28399
2018-12-31	27480
2019-03-31	30144
2019-06-30	32200
2019-09-30	30899
2019-12-31	28058
2020-03-31	34173
2020-06-30	30717
2020-09-30	33537
2020-12-31	31735
2021-03-31	35112
2021-06-30	35700
2021-09-30	35040
2021-12-31	34824
2022-03-31	40057
2022-06-30	37720
2022-09-30	40087
2022-12-31	36950
2023-03-31	37670
2023-06-30	37599
2023-09-30	33096