Quarter	US dollars
1999-03-31	7864
1999-06-30	7008
1999-09-30	6627
1999-12-31	6617
2000-03-31	7990
2000-06-30	8432
2000-09-30	8617
2000-12-31	7803
2001-03-31	10766
2001-06-30	9883
2001-09-30	11705
2001-12-31	12066
2002-03-31	10718
2002-06-30	9353
2002-09-30	9598
2002-12-31	11122
2003-03-31	9403
2003-06-30	10484
2003-09-30	10068
2003-12-31	11127
2004-03-31	10214
2004-06-30	9288
2004-09-30	7960
2004-12-31	11110
2005-03-31	11165
2005-06-30	10713
2005-09-30	14272
2005-12-31	13737
2006-03-31	13353
2006-06-30	13469
2006-09-30	15481
2006-12-31	18635
2007-03-31	19780
2007-06-30	24995
2007-09-30	22489
2007-12-31	34663
2008-03-31	31281
2008-06-30	16387
2008-09-30	19240
2008-12-31	25242
2009-03-31	19909
2009-06-30	22231
2009-09-30	22271
2009-12-31	24826
2010-03-31	20472
2010-06-30	16066
2010-09-30	14567
2010-12-31	16805
2011-03-31	23198
2011-06-30	22452
2011-09-30	13528
2011-12-31	16675
2012-03-31	17468
2012-06-30	17957
2012-09-30	19929
2012-12-31	18365
2013-03-31	26811
2013-06-30	26061
2013-09-30	28978
2013-12-31	25272
2014-03-31	27149
2014-06-30	28582
2014-09-30	30560
2014-12-31	30441
2015-03-31	25404
2015-06-30	26988
2015-09-30	30206
2015-12-31	26903
2016-03-31	24773
2016-06-30	21554
2016-09-30	24985
2016-12-31	23724
2017-03-31	28333
2017-06-30	26596
2017-09-30	28522
2017-12-31	26236
2018-03-31	30192
2018-06-30	27458
2018-09-30	31047
2018-12-31	33175
2019-03-31	38634
2019-06-30	38149
2019-09-30	30969
2019-12-31	34265
2020-03-31	32832
2020-06-30	32130
2020-09-30	30606
2020-12-31	29022
2021-03-31	24075
2021-06-30	23669
2021-09-30	22783
2021-12-31	19425
2022-03-31	21428
2022-06-30	26917
2022-09-30	25740
2022-12-31	26662
2023-03-31	33552
2023-06-30	31945
2023-09-30	28658