Quarter	US dollars
1999-03-31	2873
1999-06-30	2436
1999-09-30	2691
1999-12-31	2709
2000-03-31	3030
2000-06-30	2797
2000-09-30	2990
2000-12-31	3095
2001-03-31	2953
2001-06-30	3299
2001-09-30	3411
2001-12-31	3271
2002-03-31	3164
2002-06-30	2679
2002-09-30	3120
2002-12-31	2751
2003-03-31	2990
2003-06-30	2683
2003-09-30	2872
2003-12-31	3290
2004-03-31	3000
2004-06-30	2973
2004-09-30	3252
2004-12-31	4681
2005-03-31	4978
2005-06-30	4688
2005-09-30	4881
2005-12-31	5014
2006-03-31	4174
2006-06-30	4855
2006-09-30	6693
2006-12-31	6608
2007-03-31	6255
2007-06-30	6490
2007-09-30	6616
2007-12-31	6370
2008-03-31	6046
2008-06-30	7315
2008-09-30	7175
2008-12-31	5688
2009-03-31	4961
2009-06-30	5273
2009-09-30	4536
2009-12-31	5284
2010-03-31	4692
2010-06-30	5068
2010-09-30	7899
2010-12-31	9722
2011-03-31	10214
2011-06-30	10034
2011-09-30	8001
2011-12-31	6843
2012-03-31	8067
2012-06-30	6860
2012-09-30	5377
2012-12-31	6656
2013-03-31	7597
2013-06-30	5378
2013-09-30	8341
2013-12-31	7776
2014-03-31	7053
2014-06-30	7142
2014-09-30	7835
2014-12-31	8072
2015-03-31	8468
2015-06-30	9769
2015-09-30	12771
2015-12-31	12344
2016-03-31	11058
2016-06-30	10067
2016-09-30	9750
2016-12-31	9705
2017-03-31	9863
2017-06-30	9914
2017-09-30	8696
2017-12-31	8275
2018-03-31	7234
2018-06-30	8150
2018-09-30	6940
2018-12-31	5961
2019-03-31	6626
2019-06-30	7296
2019-09-30	7818
2019-12-31	6997
2020-03-31	8783
2020-06-30	7080
2020-09-30	7383
2020-12-31	8203
2021-03-31	8378
2021-06-30	9038
2021-09-30	9958
2021-12-31	10708
2022-03-31	10831
2022-06-30	10531
2022-09-30	11885
2022-12-31	11339
2023-03-31	11464
2023-06-30	11726
2023-09-30	11864