Quarter	US dollars
1999-03-31	173666
1999-06-30	162479
1999-09-30	166932
1999-12-31	161443
2000-03-31	167308
2000-06-30	190051
2000-09-30	195615
2000-12-31	206140
2001-03-31	218495
2001-06-30	217843
2001-09-30	229291
2001-12-31	205234
2002-03-31	244120
2002-06-30	241979
2002-09-30	252042
2002-12-31	235765
2003-03-31	250561
2003-06-30	271456
2003-09-30	296942
2003-12-31	311067
2004-03-31	339230
2004-06-30	354992
2004-09-30	371021
2004-12-31	425172
2005-03-31	443489
2005-06-30	485936
2005-09-30	485281
2005-12-31	488259
2006-03-31	517537
2006-06-30	570582
2006-09-30	559973
2006-12-31	594766
2007-03-31	593330
2007-06-30	643212
2007-09-30	723871
2007-12-31	762722
2008-03-31	762394
2008-06-30	721293
2008-09-30	700829
2008-12-31	571099
2009-03-31	599019
2009-06-30	540243
2009-09-30	560439
2009-12-31	591803
2010-03-31	572399
2010-06-30	542404
2010-09-30	575527
2010-12-31	591805
2011-03-31	611477
2011-06-30	624605
2011-09-30	613483
2011-12-31	606888
2012-03-31	588796
2012-06-30	575627
2012-09-30	556932
2012-12-31	550485
2013-03-31	553451
2013-06-30	516750
2013-09-30	537552
2013-12-31	581213
2014-03-31	630017
2014-06-30	681242
2014-09-30	669483
2014-12-31	621283
2015-03-31	600872
2015-06-30	592262
2015-09-30	575897
2015-12-31	540149
2016-03-31	539928
2016-06-30	563574
2016-09-30	560809
2016-12-31	544752
2017-03-31	547111
2017-06-30	539949
2017-09-30	566140
2017-12-31	582257
2018-03-31	597306
2018-06-30	570643
2018-09-30	547814
2018-12-31	551207
2019-03-31	553746
2019-06-30	556446
2019-09-30	529397
2019-12-31	537821
2020-03-31	570166
2020-06-30	505729
2020-09-30	504170
2020-12-31	538910
2021-03-31	558725
2021-06-30	556131
2021-09-30	572820
2021-12-31	567641
2022-03-31	584097
2022-06-30	556893
2022-09-30	542574
2022-12-31	546441
2023-03-31	584199
2023-06-30	571836
2023-09-30	504655