Quarter	US dollars
1999-03-31	7335
1999-06-30	6926
1999-09-30	6704
1999-12-31	6041
2000-03-31	6138
2000-06-30	5879
2000-09-30	6045
2000-12-31	6356
2001-03-31	6579
2001-06-30	6488
2001-09-30	6519
2001-12-31	6288
2002-03-31	6568
2002-06-30	6099
2002-09-30	6690
2002-12-31	7112
2003-03-31	6751
2003-06-30	8467
2003-09-30	10313
2003-12-31	12592
2004-03-31	17391
2004-06-30	19535
2004-09-30	20730
2004-12-31	22620
2005-03-31	21471
2005-06-30	22195
2005-09-30	26695
2005-12-31	23963
2006-03-31	29738
2006-06-30	30410
2006-09-30	32549
2006-12-31	34086
2007-03-31	33121
2007-06-30	38539
2007-09-30	23400
2007-12-31	12298
2008-03-31	8092
2008-06-30	5874
2008-09-30	4290
2008-12-31	7638
2009-03-31	9767
2009-06-30	8826
2009-09-30	5865
2009-12-31	5218
2010-03-31	7176
2010-06-30	2528
2010-09-30	3997
2010-12-31	3796
2011-03-31	5549
2011-06-30	3480
2011-09-30	3125
2011-12-31	3523
2012-03-31	4466
2012-06-30	3942
2012-09-30	3616
2012-12-31	4520
2013-03-31	7645
2013-06-30	5164
2013-09-30	6976
2013-12-31	11478
2014-03-31	12152
2014-06-30	12839
2014-09-30	13732
2014-12-31	11171
2015-03-31	10747
2015-06-30	11103
2015-09-30	13188
2015-12-31	14864
2016-03-31	18475
2016-06-30	17853
2016-09-30	19201
2016-12-31	15445
2017-03-31	18627
2017-06-30	17477
2017-09-30	17681
2017-12-31	17917
2018-03-31	17460
2018-06-30	16115
2018-09-30	18992
2018-12-31	19675
2019-03-31	23005
2019-06-30	24413
2019-09-30	25157
2019-12-31	24885
2020-03-31	25740
2020-06-30	20691
2020-09-30	15588
2020-12-31	17266
2021-03-31	27938
2021-06-30	31244
2021-09-30	33377
2021-12-31	37654
2022-03-31	39389
2022-06-30	36873
2022-09-30	36502
2022-12-31	35370
2023-03-31	30052
2023-06-30	23462
2023-09-30	32234