Quarter	US dollars
1999-03-31	35606
1999-06-30	34555
1999-09-30	38487
1999-12-31	37263
2000-03-31	38741
2000-06-30	34471
2000-09-30	36299
2000-12-31	38463
2001-03-31	36799
2001-06-30	36364
2001-09-30	36584
2001-12-31	36045
2002-03-31	33991
2002-06-30	31675
2002-09-30	32763
2002-12-31	31977
2003-03-31	30316
2003-06-30	29609
2003-09-30	28745
2003-12-31	28162
2004-03-31	31921
2004-06-30	28810
2004-09-30	28681
2004-12-31	31506
2005-03-31	29786
2005-06-30	38605
2005-09-30	41496
2005-12-31	48639
2006-03-31	52683
2006-06-30	59318
2006-09-30	52278
2006-12-31	53474
2007-03-31	61893
2007-06-30	59650
2007-09-30	72864
2007-12-31	70424
2008-03-31	83490
2008-06-30	83895
2008-09-30	84137
2008-12-31	75610
2009-03-31	77162
2009-06-30	77510
2009-09-30	72712
2009-12-31	71123
2010-03-31	65003
2010-06-30	64668
2010-09-30	72341
2010-12-31	69715
2011-03-31	71555
2011-06-30	72289
2011-09-30	69803
2011-12-31	63708
2012-03-31	67226
2012-06-30	66419
2012-09-30	67091
2012-12-31	66053
2013-03-31	60851
2013-06-30	45078
2013-09-30	45953
2013-12-31	47309
2014-03-31	48247
2014-06-30	47466
2014-09-30	46889
2014-12-31	44825
2015-03-31	37977
2015-06-30	37400
2015-09-30	34237
2015-12-31	32501
2016-03-31	31196
2016-06-30	35286
2016-09-30	35497
2016-12-31	35245
2017-03-31	36277
2017-06-30	42779
2017-09-30	47306
2017-12-31	50890
2018-03-31	52182
2018-06-30	49897
2018-09-30	52095
2018-12-31	48632
2019-03-31	48537
2019-06-30	52345
2019-09-30	53676
2019-12-31	57451
2020-03-31	58133
2020-06-30	49297
2020-09-30	46879
2020-12-31	47783
2021-03-31	44264
2021-06-30	47153
2021-09-30	46676
2021-12-31	47584
2022-03-31	47647
2022-06-30	49354
2022-09-30	55827
2022-12-31	34662
2023-03-31	30261
2023-06-30	41441
2023-09-30	41210