Quarter	US dollars
1999-03-31	7454
1999-06-30	5423
1999-09-30	6997
1999-12-31	7185
2000-03-31	6830
2000-06-30	8064
2000-09-30	7845
2000-12-31	7772
2001-03-31	8878
2001-06-30	10848
2001-09-30	12664
2001-12-31	12255
2002-03-31	11264
2002-06-30	11259
2002-09-30	14118
2002-12-31	12715
2003-03-31	15760
2003-06-30	14592
2003-09-30	15538
2003-12-31	14309
2004-03-31	15920
2004-06-30	16900
2004-09-30	14195
2004-12-31	18067
2005-03-31	18946
2005-06-30	14911
2005-09-30	18001
2005-12-31	12158
2006-03-31	18552
2006-06-30	17336
2006-09-30	21817
2006-12-31	19178
2007-03-31	22788
2007-06-30	29693
2007-09-30	22788
2007-12-31	21910
2008-03-31	27952
2008-06-30	26666
2008-09-30	17910
2008-12-31	15218
2009-03-31	20373
2009-06-30	19573
2009-09-30	21281
2009-12-31	14862
2010-03-31	15384
2010-06-30	15915
2010-09-30	13637
2010-12-31	12575
2011-03-31	14233
2011-06-30	14457
2011-09-30	17379
2011-12-31	13386
2012-03-31	14271
2012-06-30	13333
2012-09-30	12461
2012-12-31	12339
2013-03-31	11241
2013-06-30	10667
2013-09-30	12224
2013-12-31	10168
2014-03-31	10188
2014-06-30	10890
2014-09-30	10386
2014-12-31	9555
2015-03-31	9710
2015-06-30	7051
2015-09-30	7130
2015-12-31	5723
2016-03-31	8190
2016-06-30	7435
2016-09-30	7235
2016-12-31	5627
2017-03-31	5864
2017-06-30	5851
2017-09-30	6025
2017-12-31	5516
2018-03-31	6378
2018-06-30	6824
2018-09-30	5674
2018-12-31	5652
2019-03-31	6463
2019-06-30	5968
2019-09-30	5487
2019-12-31	4548
2020-03-31	5034
2020-06-30	4459
2020-09-30	5149
2020-12-31	5042
2021-03-31	4763
2021-06-30	5349
2021-09-30	3671
2021-12-31	3342
2022-03-31	4159
2022-06-30	3499
2022-09-30	3617
2022-12-31	2822
2023-03-31	2583
2023-06-30	2410
2023-09-30	3104