Quarter	US dollars
1999-03-31	30577
1999-06-30	37130
1999-09-30	31594
1999-12-31	26182
2000-03-31	29422
2000-06-30	27009
2000-09-30	25121
2000-12-31	26010
2001-03-31	26557
2001-06-30	26299
2001-09-30	29791
2001-12-31	25724
2002-03-31	26852
2002-06-30	23293
2002-09-30	30889
2002-12-31	24966
2003-03-31	33808
2003-06-30	32846
2003-09-30	36126
2003-12-31	37999
2004-03-31	50631
2004-06-30	41324
2004-09-30	41609
2004-12-31	44024
2005-03-31	39130
2005-06-30	39700
2005-09-30	45037
2005-12-31	47738
2006-03-31	45034
2006-06-30	51785
2006-09-30	35854
2006-12-31	27351
2007-03-31	31943
2007-06-30	32158
2007-09-30	31096
2007-12-31	32154
2008-03-31	52530
2008-06-30	56033
2008-09-30	53355
2008-12-31	84786
2009-03-31	20781
2009-06-30	19241
2009-09-30	29585
2009-12-31	26639
2010-03-31	30618
2010-06-30	44246
2010-09-30	25511
2010-12-31	20939
2011-03-31	23227
2011-06-30	24244
2011-09-30	28210
2011-12-31	42230
2012-03-31	56441
2012-06-30	47133
2012-09-30	34624
2012-12-31	26222
2013-03-31	19526
2013-06-30	20827
2013-09-30	19383
2013-12-31	21636
2014-03-31	18765
2014-06-30	18676
2014-09-30	16344
2014-12-31	13182
2015-03-31	17722
2015-06-30	15152
2015-09-30	15938
2015-12-31	10359
2016-03-31	9518
2016-06-30	12300
2016-09-30	19905
2016-12-31	20835
2017-03-31	13029
2017-06-30	22086
2017-09-30	16818
2017-12-31	24269
2018-03-31	18602
2018-06-30	24763
2018-09-30	20461
2018-12-31	18029
2019-03-31	20132
2019-06-30	15717
2019-09-30	19497
2019-12-31	13159
2020-03-31	16210
2020-06-30	18505
2020-09-30	16554
2020-12-31	35712
2021-03-31	29712
2021-06-30	42493
2021-09-30	29200
2021-12-31	42548
2022-03-31	31631
2022-06-30	35037
2022-09-30	18629
2022-12-31	8568
2023-03-31	17026
2023-06-30	10673
2023-09-30	11983