Quarter	US dollars
1999-03-31	9334
1999-06-30	9067
1999-09-30	9239
1999-12-31	8850
2000-03-31	8762
2000-06-30	10870
2000-09-30	10798
2000-12-31	10006
2001-03-31	9105
2001-06-30	8520
2001-09-30	12585
2001-12-31	9456
2002-03-31	11577
2002-06-30	13345
2002-09-30	12180
2002-12-31	12014
2003-03-31	13353
2003-06-30	12206
2003-09-30	11626
2003-12-31	12767
2004-03-31	11979
2004-06-30	14332
2004-09-30	15788
2004-12-31	17054
2005-03-31	15790
2005-06-30	15099
2005-09-30	15306
2005-12-31	17911
2006-03-31	18921
2006-06-30	18446
2006-09-30	19304
2006-12-31	17592
2007-03-31	15203
2007-06-30	20458
2007-09-30	22735
2007-12-31	26429
2008-03-31	25383
2008-06-30	30586
2008-09-30	26318
2008-12-31	27701
2009-03-31	24009
2009-06-30	24508
2009-09-30	22503
2009-12-31	20238
2010-03-31	26099
2010-06-30	22701
2010-09-30	18716
2010-12-31	21193
2011-03-31	25871
2011-06-30	24364
2011-09-30	23422
2011-12-31	23015
2012-03-31	21041
2012-06-30	20505
2012-09-30	20389
2012-12-31	8514
2013-03-31	11516
2013-06-30	11610
2013-09-30	11105
2013-12-31	11622
2014-03-31	13769
2014-06-30	12916
2014-09-30	12160
2014-12-31	12950
2015-03-31	12583
2015-06-30	11633
2015-09-30	6412
2015-12-31	5523
2016-03-31	4823
2016-06-30	5197
2016-09-30	5152
2016-12-31	5043
2017-03-31	5170
2017-06-30	5649
2017-09-30	6301
2017-12-31	5724
2018-03-31	5417
2018-06-30	5156
2018-09-30	5402
2018-12-31	5450
2019-03-31	6784
2019-06-30	7105
2019-09-30	5964
2019-12-31	5944
2020-03-31	7633
2020-06-30	7414
2020-09-30	7235
2020-12-31	5649
2021-03-31	6480
2021-06-30	5571
2021-09-30	6049
2021-12-31	5500
2022-03-31	5882
2022-06-30	5656
2022-09-30	4575
2022-12-31	6017
2023-03-31	5190
2023-06-30	6777
2023-09-30	6748