Quarter	US dollars
1999-03-31	34301
1999-06-30	34269
1999-09-30	33270
1999-12-31	34089
2000-03-31	36496
2000-06-30	36180
2000-09-30	33065
2000-12-31	36966
2001-03-31	38593
2001-06-30	31010
2001-09-30	37708
2001-12-31	34273
2002-03-31	32932
2002-06-30	39040
2002-09-30	39428
2002-12-31	40206
2003-03-31	42167
2003-06-30	43177
2003-09-30	43642
2003-12-31	51897
2004-03-31	53058
2004-06-30	45555
2004-09-30	42263
2004-12-31	50065
2005-03-31	48667
2005-06-30	42913
2005-09-30	55220
2005-12-31	46079
2006-03-31	50519
2006-06-30	52773
2006-09-30	54930
2006-12-31	52264
2007-03-31	63185
2007-06-30	59352
2007-09-30	61192
2007-12-31	67207
2008-03-31	78506
2008-06-30	87925
2008-09-30	88714
2008-12-31	100829
2009-03-31	53090
2009-06-30	53500
2009-09-30	48373
2009-12-31	51488
2010-03-31	54286
2010-06-30	35627
2010-09-30	38866
2010-12-31	35204
2011-03-31	36888
2011-06-30	37968
2011-09-30	39354
2011-12-31	42628
2012-03-31	42574
2012-06-30	42230
2012-09-30	45962
2012-12-31	45458
2013-03-31	34129
2013-06-30	36431
2013-09-30	39260
2013-12-31	48837
2014-03-31	48850
2014-06-30	57108
2014-09-30	54625
2014-12-31	51356
2015-03-31	50397
2015-06-30	53855
2015-09-30	51517
2015-12-31	40145
2016-03-31	38186
2016-06-30	43481
2016-09-30	41242
2016-12-31	38656
2017-03-31	43163
2017-06-30	44432
2017-09-30	49713
2017-12-31	42045
2018-03-31	40947
2018-06-30	35321
2018-09-30	42502
2018-12-31	34647
2019-03-31	33901
2019-06-30	31931
2019-09-30	35343
2019-12-31	32625
2020-03-31	41587
2020-06-30	34811
2020-09-30	34409
2020-12-31	44444
2021-03-31	35266
2021-06-30	34339
2021-09-30	36605
2021-12-31	29661
2022-03-31	17515
2022-06-30	14529
2022-09-30	14679
2022-12-31	16356
2023-03-31	14917
2023-06-30	14946
2023-09-30	15120