Quarter	US dollars
1999-03-31	14327
1999-06-30	13354
1999-09-30	17534
1999-12-31	17907
2000-03-31	18550
2000-06-30	19003
2000-09-30	19859
2000-12-31	22067
2001-03-31	22901
2001-06-30	22471
2001-09-30	22739
2001-12-31	23792
2002-03-31	25774
2002-06-30	28878
2002-09-30	31861
2002-12-31	33972
2003-03-31	35688
2003-06-30	44183
2003-09-30	47921
2003-12-31	58761
2004-03-31	65606
2004-06-30	67274
2004-09-30	61257
2004-12-31	71733
2005-03-31	74660
2005-06-30	72291
2005-09-30	87017
2005-12-31	97204
2006-03-31	89254
2006-06-30	94553
2006-09-30	103233
2006-12-31	118963
2007-03-31	126980
2007-06-30	133525
2007-09-30	131745
2007-12-31	153320
2008-03-31	182933
2008-06-30	187489
2008-09-30	178683
2008-12-31	156556
2009-03-31	163107
2009-06-30	178481
2009-09-30	170893
2009-12-31	168564
2010-03-31	162544
2010-06-30	168570
2010-09-30	185669
2010-12-31	154034
2011-03-31	152894
2011-06-30	151252
2011-09-30	144424
2011-12-31	133076
2012-03-31	128121
2012-06-30	126141
2012-09-30	127369
2012-12-31	116063
2013-03-31	112008
2013-06-30	104645
2013-09-30	103917
2013-12-31	108514
2014-03-31	112292
2014-06-30	105065
2014-09-30	102617
2014-12-31	97283
2015-03-31	90969
2015-06-30	78284
2015-09-30	64812
2015-12-31	69989
2016-03-31	75897
2016-06-30	76454
2016-09-30	68011
2016-12-31	58244
2017-03-31	57102
2017-06-30	51270
2017-09-30	56976
2017-12-31	56890
2018-03-31	63634
2018-06-30	64285
2018-09-30	66397
2018-12-31	66102
2019-03-31	63055
2019-06-30	52458
2019-09-30	54328
2019-12-31	59095
2020-03-31	58128
2020-06-30	60745
2020-09-30	61995
2020-12-31	78084
2021-03-31	61943
2021-06-30	70829
2021-09-30	73634
2021-12-31	71474
2022-03-31	60175
2022-06-30	53131
2022-09-30	49301
2022-12-31	50197
2023-03-31	51071
2023-06-30	52344
2023-09-30	50022