Quarter	US dollars
1999-03-31	1006
1999-06-30	1030
1999-09-30	1323
1999-12-31	1410
2000-03-31	1228
2000-06-30	1113
2000-09-30	1130
2000-12-31	1129
2001-03-31	1081
2001-06-30	1076
2001-09-30	1070
2001-12-31	1142
2002-03-31	1319
2002-06-30	1139
2002-09-30	1021
2002-12-31	819
2003-03-31	1536
2003-06-30	1975
2003-09-30	1406
2003-12-31	2043
2004-03-31	1882
2004-06-30	1285
2004-09-30	1117
2004-12-31	1468
2005-03-31	1666
2005-06-30	2101
2005-09-30	3395
2005-12-31	1984
2006-03-31	2516
2006-06-30	2438
2006-09-30	2146
2006-12-31	2098
2007-03-31	1938
2007-06-30	2828
2007-09-30	2625
2007-12-31	3566
2008-03-31	4282
2008-06-30	3885
2008-09-30	3606
2008-12-31	2386
2009-03-31	2177
2009-06-30	2287
2009-09-30	2739
2009-12-31	2381
2010-03-31	2612
2010-06-30	2598
2010-09-30	3864
2010-12-31	3289
2011-03-31	2725
2011-06-30	3236
2011-09-30	2827
2011-12-31	3490
2012-03-31	3050
2012-06-30	3079
2012-09-30	2376
2012-12-31	2252
2013-03-31	3065
2013-06-30	3132
2013-09-30	3337
2013-12-31	3289
2014-03-31	3416
2014-06-30	3771
2014-09-30	3803
2014-12-31	4816
2015-03-31	4477
2015-06-30	4500
2015-09-30	5765
2015-12-31	4844
2016-03-31	5832
2016-06-30	5682
2016-09-30	4939
2016-12-31	5922
2017-03-31	6278
2017-06-30	6617
2017-09-30	5740
2017-12-31	6467
2018-03-31	6814
2018-06-30	4209
2018-09-30	5254
2018-12-31	5690
2019-03-31	5085
2019-06-30	5901
2019-09-30	6610
2019-12-31	6617
2020-03-31	5322
2020-06-30	6537
2020-09-30	6638
2020-12-31	5157
2021-03-31	5045
2021-06-30	4888
2021-09-30	5228
2021-12-31	7554
2022-03-31	6652
2022-06-30	6931
2022-09-30	7678
2022-12-31	8375
2023-03-31	6856
2023-06-30	8361
2023-09-30	8127