Quarter	US dollars
1999-03-31	67333
1999-06-30	60926
1999-09-30	58951
1999-12-31	62768
2000-03-31	64766
2000-06-30	67874
2000-09-30	73068
2000-12-31	79319
2001-03-31	89912
2001-06-30	98907
2001-09-30	105458
2001-12-31	104986
2002-03-31	129418
2002-06-30	142786
2002-09-30	149967
2002-12-31	129579
2003-03-31	133010
2003-06-30	145141
2003-09-30	163534
2003-12-31	173727
2004-03-31	179450
2004-06-30	197562
2004-09-30	219143
2004-12-31	244273
2005-03-31	269897
2005-06-30	291368
2005-09-30	308480
2005-12-31	300383
2006-03-31	315202
2006-06-30	341093
2006-09-30	341045
2006-12-31	373055
2007-03-31	381968
2007-06-30	408072
2007-09-30	445015
2007-12-31	504632
2008-03-31	492024
2008-06-30	463978
2008-09-30	442610
2008-12-31	360077
2009-03-31	346038
2009-06-30	337935
2009-09-30	333028
2009-12-31	361754
2010-03-31	349553
2010-06-30	307160
2010-09-30	318118
2010-12-31	321157
2011-03-31	325845
2011-06-30	315638
2011-09-30	307473
2011-12-31	293329
2012-03-31	295679
2012-06-30	285767
2012-09-30	290233
2012-12-31	283206
2013-03-31	288204
2013-06-30	262691
2013-09-30	262787
2013-12-31	274650
2014-03-31	297766
2014-06-30	319785
2014-09-30	309712
2014-12-31	310426
2015-03-31	314542
2015-06-30	316630
2015-09-30	329257
2015-12-31	299784
2016-03-31	301380
2016-06-30	298677
2016-09-30	282733
2016-12-31	288016
2017-03-31	281257
2017-06-30	280898
2017-09-30	295510
2017-12-31	316766
2018-03-31	317667
2018-06-30	303364
2018-09-30	294429
2018-12-31	327215
2019-03-31	319957
2019-06-30	319588
2019-09-30	302734
2019-12-31	315204
2020-03-31	320148
2020-06-30	312054
2020-09-30	315297
2020-12-31	334115
2021-03-31	332669
2021-06-30	342120
2021-09-30	341598
2021-12-31	345690
2022-03-31	333792
2022-06-30	327893
2022-09-30	297235
2022-12-31	304670
2023-03-31	314071
2023-06-30	313415
2023-09-30	297440