Quarter	US dollars
1999-03-31	3456
1999-06-30	3374
1999-09-30	4196
1999-12-31	3203
2000-03-31	4821
2000-06-30	6680
2000-09-30	5420
2000-12-31	3091
2001-03-31	3811
2001-06-30	4863
2001-09-30	6957
2001-12-31	5845
2002-03-31	5196
2002-06-30	4856
2002-09-30	2467
2002-12-31	3914
2003-03-31	5123
2003-06-30	7025
2003-09-30	8533
2003-12-31	6384
2004-03-31	7000
2004-06-30	11779
2004-09-30	12611
2004-12-31	9032
2005-03-31	10926
2005-06-30	10010
2005-09-30	6480
2005-12-31	5820
2006-03-31	7265
2006-06-30	9195
2006-09-30	8277
2006-12-31	7892
2007-03-31	7301
2007-06-30	9435
2007-09-30	8024
2007-12-31	9344
2008-03-31	8054
2008-06-30	11456
2008-09-30	10645
2008-12-31	11935
2009-03-31	17418
2009-06-30	24038
2009-09-30	23718
2009-12-31	24777
2010-03-31	9772
2010-06-30	6630
2010-09-30	7610
2010-12-31	6442
2011-03-31	6948
2011-06-30	8058
2011-09-30	14064
2011-12-31	12240
2012-03-31	9435
2012-06-30	8830
2012-09-30	10374
2012-12-31	10601
2013-03-31	9896
2013-06-30	12125
2013-09-30	12238
2013-12-31	10530
2014-03-31	9685
2014-06-30	10889
2014-09-30	10231
2014-12-31	8712
2015-03-31	9914
2015-06-30	8831
2015-09-30	10018
2015-12-31	9840
2016-03-31	9326
2016-06-30	9984
2016-09-30	9273
2016-12-31	10042
2017-03-31	8877
2017-06-30	9584
2017-09-30	10661
2017-12-31	10765
2018-03-31	11346
2018-06-30	14223
2018-09-30	12777
2018-12-31	9034
2019-03-31	10261
2019-06-30	9945
2019-09-30	9709
2019-12-31	15688
2020-03-31	15263
2020-06-30	17533
2020-09-30	12019
2020-12-31	11619
2021-03-31	11578
2021-06-30	11013
2021-09-30	9665
2021-12-31	13518
2022-03-31	12897
2022-06-30	8767
2022-09-30	8689
2022-12-31	9772
2023-03-31	7038
2023-06-30	6580
2023-09-30	7182