Quarter	US dollars
1999-03-31	14172
1999-06-30	11670
1999-09-30	13254
1999-12-31	10494
2000-03-31	12966
2000-06-30	13851
2000-09-30	13209
2000-12-31	14585
2001-03-31	12989
2001-06-30	10707
2001-09-30	14581
2001-12-31	11066
2002-03-31	10863
2002-06-30	16819
2002-09-30	15937
2002-12-31	13287
2003-03-31	14716
2003-06-30	15662
2003-09-30	12400
2003-12-31	11906
2004-03-31	12575
2004-06-30	14526
2004-09-30	16122
2004-12-31	15215
2005-03-31	18910
2005-06-30	19191
2005-09-30	19571
2005-12-31	17026
2006-03-31	19226
2006-06-30	18790
2006-09-30	21231
2006-12-31	22633
2007-03-31	27742
2007-06-30	24003
2007-09-30	25557
2007-12-31	29089
2008-03-31	29082
2008-06-30	32139
2008-09-30	29292
2008-12-31	30356
2009-03-31	27261
2009-06-30	28097
2009-09-30	26516
2009-12-31	32923
2010-03-31	40903
2010-06-30	37918
2010-09-30	37077
2010-12-31	29338
2011-03-31	29498
2011-06-30	29315
2011-09-30	28010
2011-12-31	23691
2012-03-31	22577
2012-06-30	20399
2012-09-30	19206
2012-12-31	19607
2013-03-31	17924
2013-06-30	17700
2013-09-30	18613
2013-12-31	18141
2014-03-31	18949
2014-06-30	19079
2014-09-30	16638
2014-12-31	17150
2015-03-31	15236
2015-06-30	15351
2015-09-30	15911
2015-12-31	15571
2016-03-31	16212
2016-06-30	16373
2016-09-30	12495
2016-12-31	10806
2017-03-31	9606
2017-06-30	9826
2017-09-30	10148
2017-12-31	10166
2018-03-31	10148
2018-06-30	6879
2018-09-30	7069
2018-12-31	7198
2019-03-31	5789
2019-06-30	6676
2019-09-30	7257
2019-12-31	6375
2020-03-31	7123
2020-06-30	4993
2020-09-30	5130
2020-12-31	4386
2021-03-31	2955
2021-06-30	2752
2021-09-30	2670
2021-12-31	2578
2022-03-31	1610
2022-06-30	1287
2022-09-30	1226
2022-12-31	1345
2023-03-31	1389
2023-06-30	917
2023-09-30	897