Quarter	US dollars
1999-03-31	1692
1999-06-30	1448
1999-09-30	1458
1999-12-31	1645
2000-03-31	1505
2000-06-30	1350
2000-09-30	1559
2000-12-31	1867
2001-03-31	2118
2001-06-30	2232
2001-09-30	2343
2001-12-31	2157
2002-03-31	2630
2002-06-30	2274
2002-09-30	2172
2002-12-31	2411
2003-03-31	2730
2003-06-30	2979
2003-09-30	2703
2003-12-31	3247
2004-03-31	3680
2004-06-30	3721
2004-09-30	3804
2004-12-31	3812
2005-03-31	3714
2005-06-30	3672
2005-09-30	4172
2005-12-31	5461
2006-03-31	6679
2006-06-30	5031
2006-09-30	8543
2006-12-31	7049
2007-03-31	7911
2007-06-30	6611
2007-09-30	9305
2007-12-31	7935
2008-03-31	6817
2008-06-30	11066
2008-09-30	8873
2008-12-31	7638
2009-03-31	10567
2009-06-30	8954
2009-09-30	9033
2009-12-31	8461
2010-03-31	9740
2010-06-30	8621
2010-09-30	9375
2010-12-31	9955
2011-03-31	13110
2011-06-30	11527
2011-09-30	9686
2011-12-31	8828
2012-03-31	11114
2012-06-30	9834
2012-09-30	12089
2012-12-31	11584
2013-03-31	12877
2013-06-30	11290
2013-09-30	11151
2013-12-31	10844
2014-03-31	11878
2014-06-30	11775
2014-09-30	13397
2014-12-31	13583
2015-03-31	16516
2015-06-30	16931
2015-09-30	14243
2015-12-31	14917
2016-03-31	13149
2016-06-30	15235
2016-09-30	16518
2016-12-31	14249
2017-03-31	16388
2017-06-30	17510
2017-09-30	14749
2017-12-31	13360
2018-03-31	15472
2018-06-30	13378
2018-09-30	14014
2018-12-31	11867
2019-03-31	18049
2019-06-30	18918
2019-09-30	15592
2019-12-31	15102
2020-03-31	15769
2020-06-30	13299
2020-09-30	14401
2020-12-31	13712
2021-03-31	14482
2021-06-30	14818
2021-09-30	12903
2021-12-31	11827
2022-03-31	10166
2022-06-30	9865
2022-09-30	10751
2022-12-31	10125
2023-03-31	11692
2023-06-30	11099
2023-09-30	10587