Quarter	US dollars
1997-09-30	20553
1997-12-31	17905
1998-03-31	15675
1998-06-30	14881
1998-09-30	15249
1998-12-31	15770
1999-03-31	13538
1999-06-30	13349
1999-09-30	10892
1999-12-31	11907
2000-03-31	8950
2000-06-30	11329
2000-09-30	11173
2000-12-31	14930
2001-03-31	13937
2001-06-30	13887
2001-09-30	16908
2001-12-31	15818
2002-03-31	16172
2002-06-30	17907
2002-09-30	17082
2002-12-31	18596
2003-03-31	17071
2003-06-30	16597
2003-09-30	15394
2003-12-31	16481
2004-03-31	16524
2004-06-30	17398
2004-09-30	18433
2004-12-31	21636
2005-03-31	21427
2005-06-30	21808
2005-09-30	21224
2005-12-31	23077
2006-03-31	23792
2006-06-30	23599
2006-09-30	24201
2006-12-31	26895
2007-03-31	26110
2007-06-30	26796
2007-09-30	26134
2007-12-31	28885
2008-03-31	28375
2008-06-30	26528
2008-09-30	22716
2008-12-31	23985
2009-03-31	21554
2009-06-30	23544
2009-09-30	22606
2009-12-31	22207
2010-03-31	19216
2010-06-30	18048
2010-09-30	21940
2010-12-31	21423
2011-03-31	23709
2011-06-30	28123
2011-09-30	28538
2011-12-31	27519
2012-03-31	28583
2012-06-30	27829
2012-09-30	28730
2012-12-31	29827
2013-03-31	30275
2013-06-30	32129
2013-09-30	33717
2013-12-31	36007
2014-03-31	38043
2014-06-30	38166
2014-09-30	33873
2014-12-31	33934
2015-03-31	40250
2015-06-30	41267
2015-09-30	42848
2015-12-31	43637
2016-03-31	48783
2016-06-30	47946
2016-09-30	49758
2016-12-31	44805
2017-03-31	51542
2017-06-30	57461
2017-09-30	55263
2017-12-31	58572
2018-03-31	62903
2018-06-30	57533
2018-09-30	55984
2018-12-31	71195
2019-03-31	61695
2019-06-30	49505
2019-09-30	51970
2019-12-31	69863
2020-03-31	52933
2020-06-30	46545
2020-09-30	46263
2020-12-31	61631
2021-03-31	47055
2021-06-30	45382
2021-09-30	49152
2021-12-31	49114
2022-03-31	43685
2022-06-30	41264
2022-09-30	39149
2022-12-31	46929
2023-03-31	41755
2023-06-30	39144
2023-09-30	37695
2023-12-31	40255