Quarter	US dollars
1999-03-31	1688
1999-06-30	2475
1999-09-30	2180
1999-12-31	1686
2000-03-31	2427
2000-06-30	1519
2000-09-30	1431
2000-12-31	1788
2001-03-31	1822
2001-06-30	1934
2001-09-30	2091
2001-12-31	1428
2002-03-31	2018
2002-06-30	1388
2002-09-30	2035
2002-12-31	1488
2003-03-31	1697
2003-06-30	1467
2003-09-30	1995
2003-12-31	1452
2004-03-31	1437
2004-06-30	1534
2004-09-30	1350
2004-12-31	1427
2005-03-31	1420
2005-06-30	1594
2005-09-30	2014
2005-12-31	1168
2006-03-31	1481
2006-06-30	1499
2006-09-30	1928
2006-12-31	2687
2007-03-31	1763
2007-06-30	1747
2007-09-30	1950
2007-12-31	1844
2008-03-31	2648
2008-06-30	2274
2008-09-30	1677
2008-12-31	1748
2009-03-31	1275
2009-06-30	1418
2009-09-30	1649
2009-12-31	1456
2010-03-31	1757
2010-06-30	2204
2010-09-30	1700
2010-12-31	1268
2011-03-31	2480
2011-06-30	2341
2011-09-30	2894
2011-12-31	4256
2012-03-31	4314
2012-06-30	3410
2012-09-30	2732
2012-12-31	2147
2013-03-31	2485
2013-06-30	1985
2013-09-30	2093
2013-12-31	2247
2014-03-31	28539
2014-06-30	26305
2014-09-30	21784
2014-12-31	17077
2015-03-31	18195
2015-06-30	18007
2015-09-30	16761
2015-12-31	14863
2016-03-31	24015
2016-06-30	23574
2016-09-30	28691
2016-12-31	24690
2017-03-31	29326
2017-06-30	29105
2017-09-30	29563
2017-12-31	31852
2018-03-31	34366
2018-06-30	39606
2018-09-30	40804
2018-12-31	33488
2019-03-31	40370
2019-06-30	42226
2019-09-30	32637
2019-12-31	36438
2020-03-31	33438
2020-06-30	34641
2020-09-30	32685
2020-12-31	33526
2021-03-31	36706
2021-06-30	36580
2021-09-30	32439
2021-12-31	31543
2022-03-31	40327
2022-06-30	33023
2022-09-30	33153
2022-12-31	30260
2023-03-31	35420
2023-06-30	40018
2023-09-30	37624