Quarter	US dollars
1999-03-31	24
1999-06-30	15
1999-09-30	16
1999-12-31	17
2000-03-31	12
2000-06-30	22
2000-09-30	7
2000-12-31	4
2001-03-31	1
2001-06-30	1
2001-09-30	2
2001-12-31	3
2002-03-31	5
2002-06-30	5
2002-09-30	1
2002-12-31	3
2003-03-31	2
2003-06-30	1
2003-09-30	1
2003-12-31	3
2004-03-31	1
2004-06-30	2
2004-09-30	3
2004-12-31	2
2005-03-31	4
2005-06-30	5
2005-09-30	3
2005-12-31	2
2006-03-31	2
2006-06-30	2
2006-09-30	6
2006-12-31	5
2007-03-31	3
2007-06-30	2
2007-09-30	2
2007-12-31	1
2008-03-31	13
2008-06-30	18
2008-09-30	19
2008-12-31	11
2009-03-31	15
2009-06-30	14
2009-09-30	12
2009-12-31	11
2010-03-31	11
2010-06-30	12
2010-09-30	14
2010-12-31	21
2011-03-31	20
2011-06-30	10
2011-09-30	13
2011-12-31	36
2012-03-31	45
2012-06-30	45
2012-09-30	14
2012-12-31	11
2013-03-31	373
2013-06-30	350
2013-09-30	297
2013-12-31	460
2014-03-31	447
2014-06-30	886
2014-09-30	884
2014-12-31	836
2015-03-31	806
2015-06-30	778
2015-09-30	646
2015-12-31	715
2016-03-31	755
2016-06-30	717
2016-09-30	713
2016-12-31	650
2017-03-31	724
2017-06-30	767
2017-09-30	797
2017-12-31	804
2018-03-31	1205
2018-06-30	1323
2018-09-30	1325
2018-12-31	1348
2019-03-31	1359
2019-06-30	1347
2019-09-30	1352
2019-12-31	1404
2020-03-31	1458
2020-06-30	1445
2020-09-30	1464
2020-12-31	1496
2021-03-31	1558
2021-06-30	1212
2021-09-30	1238
2021-12-31	1270
2022-03-31	458
2022-06-30	482
2022-09-30	489
2022-12-31	480
2023-03-31	482
2023-06-30	488
2023-09-30	209