Quarter	US dollars
1999-03-31	1562
1999-06-30	1602
1999-09-30	1661
1999-12-31	1656
2000-03-31	1753
2000-06-30	1694
2000-09-30	1502
2000-12-31	1635
2001-03-31	1547
2001-06-30	1868
2001-09-30	1654
2001-12-31	1553
2002-03-31	1539
2002-06-30	1416
2002-09-30	1506
2002-12-31	1562
2003-03-31	1570
2003-06-30	1525
2003-09-30	1516
2003-12-31	1697
2004-03-31	1851
2004-06-30	1833
2004-09-30	2336
2004-12-31	2230
2005-03-31	2326
2005-06-30	2370
2005-09-30	2855
2005-12-31	2660
2006-03-31	3151
2006-06-30	3919
2006-09-30	3756
2006-12-31	4949
2007-03-31	4310
2007-06-30	4165
2007-09-30	4263
2007-12-31	4064
2008-03-31	4108
2008-06-30	4088
2008-09-30	3757
2008-12-31	3746
2009-03-31	5133
2009-06-30	4028
2009-09-30	3812
2009-12-31	4303
2010-03-31	4223
2010-06-30	4064
2010-09-30	4223
2010-12-31	4294
2011-03-31	4453
2011-06-30	4811
2011-09-30	3621
2011-12-31	3222
2012-03-31	3152
2012-06-30	3434
2012-09-30	3715
2012-12-31	2487
2013-03-31	2587
2013-06-30	2578
2013-09-30	2760
2013-12-31	2729
2014-03-31	2714
2014-06-30	2874
2014-09-30	2787
2014-12-31	1979
2015-03-31	1824
2015-06-30	2041
2015-09-30	1868
2015-12-31	1929
2016-03-31	2452
2016-06-30	1905
2016-09-30	1933
2016-12-31	1848
2017-03-31	2214
2017-06-30	1953
2017-09-30	2189
2017-12-31	1850
2018-03-31	2227
2018-06-30	2059
2018-09-30	2278
2018-12-31	2718
2019-03-31	3162
2019-06-30	2714
2019-09-30	2915
2019-12-31	3298
2020-03-31	3728
2020-06-30	2388
2020-09-30	2792
2020-12-31	2927
2021-03-31	3057
2021-06-30	3043
2021-09-30	3092
2021-12-31	3342
2022-03-31	3328
2022-06-30	3335
2022-09-30	3383
2022-12-31	3085
2023-03-31	3295
2023-06-30	3060
2023-09-30	3162