Quarter	US dollars
1999-03-31	1659
1999-06-30	1550
1999-09-30	1441
1999-12-31	1614
2000-03-31	1766
2000-06-30	1890
2000-09-30	1938
2000-12-31	1978
2001-03-31	2425
2001-06-30	2499
2001-09-30	2447
2001-12-31	2611
2002-03-31	3226
2002-06-30	3206
2002-09-30	3678
2002-12-31	2976
2003-03-31	3085
2003-06-30	3033
2003-09-30	3308
2003-12-31	2909
2004-03-31	2865
2004-06-30	3107
2004-09-30	2692
2004-12-31	3231
2005-03-31	3200
2005-06-30	3516
2005-09-30	3421
2005-12-31	3056
2006-03-31	3975
2006-06-30	3478
2006-09-30	3264
2006-12-31	4056
2007-03-31	4919
2007-06-30	4415
2007-09-30	4679
2007-12-31	5359
2008-03-31	4041
2008-06-30	4949
2008-09-30	4005
2008-12-31	4348
2009-03-31	4212
2009-06-30	3911
2009-09-30	4856
2009-12-31	4415
2010-03-31	5196
2010-06-30	4198
2010-09-30	5650
2010-12-31	4157
2011-03-31	5084
2011-06-30	4972
2011-09-30	3331
2011-12-31	3416
2012-03-31	4907
2012-06-30	3628
2012-09-30	4821
2012-12-31	4969
2013-03-31	5144
2013-06-30	4762
2013-09-30	4504
2013-12-31	4383
2014-03-31	3309
2014-06-30	4380
2014-09-30	4191
2014-12-31	3946
2015-03-31	3524
2015-06-30	4071
2015-09-30	3693
2015-12-31	3403
2016-03-31	3675
2016-06-30	3641
2016-09-30	3613
2016-12-31	3612
2017-03-31	3867
2017-06-30	4193
2017-09-30	4139
2017-12-31	4351
2018-03-31	4547
2018-06-30	4492
2018-09-30	4069
2018-12-31	3352
2019-03-31	4091
2019-06-30	4255
2019-09-30	4474
2019-12-31	4503
2020-03-31	4446
2020-06-30	3308
2020-09-30	3655
2020-12-31	3451
2021-03-31	2614
2021-06-30	2401
2021-09-30	2379
2021-12-31	2329
2022-03-31	2005
2022-06-30	2383
2022-09-30	2054
2022-12-31	1801
2023-03-31	2382
2023-06-30	2585
2023-09-30	2142