Quarter	US dollars
1999-03-31	4077
1999-06-30	3970
1999-09-30	3363
1999-12-31	3735
2000-03-31	3549
2000-06-30	3552
2000-09-30	3440
2000-12-31	3531
2001-03-31	2830
2001-06-30	2646
2001-09-30	2140
2001-12-31	1683
2002-03-31	1615
2002-06-30	1649
2002-09-30	1687
2002-12-31	1634
2003-03-31	1678
2003-06-30	1721
2003-09-30	1808
2003-12-31	1951
2004-03-31	2160
2004-06-30	2348
2004-09-30	2446
2004-12-31	2368
2005-03-31	2299
2005-06-30	2350
2005-09-30	3336
2005-12-31	3264
2006-03-31	3376
2006-06-30	3459
2006-09-30	3600
2006-12-31	3428
2007-03-31	3304
2007-06-30	4873
2007-09-30	4513
2007-12-31	4540
2008-03-31	4403
2008-06-30	4725
2008-09-30	3754
2008-12-31	3223
2009-03-31	2905
2009-06-30	2655
2009-09-30	2248
2009-12-31	2092
2010-03-31	2460
2010-06-30	2293
2010-09-30	2409
2010-12-31	2364
2011-03-31	2426
2011-06-30	2263
2011-09-30	2219
2011-12-31	1976
2012-03-31	2326
2012-06-30	1884
2012-09-30	1625
2012-12-31	1415
2013-03-31	1335
2013-06-30	1478
2013-09-30	1521
2013-12-31	1382
2014-03-31	1457
2014-06-30	1641
2014-09-30	1185
2014-12-31	1134
2015-03-31	1263
2015-06-30	1475
2015-09-30	1768
2015-12-31	1705
2016-03-31	1867
2016-06-30	1911
2016-09-30	2024
2016-12-31	1541
2017-03-31	1918
2017-06-30	1652
2017-09-30	2697
2017-12-31	3029
2018-03-31	3220
2018-06-30	3011
2018-09-30	3831
2018-12-31	3855
2019-03-31	3012
2019-06-30	2398
2019-09-30	1202
2019-12-31	1201
2020-03-31	946
2020-06-30	677
2020-09-30	647
2020-12-31	555
2021-03-31	524
2021-06-30	605
2021-09-30	541
2021-12-31	517
2022-03-31	448
2022-06-30	276
2022-09-30	310
2022-12-31	308
2023-03-31	408
2023-06-30	332
2023-09-30	302