Quarter	US dollars
1999-03-31	1020
1999-06-30	990
1999-09-30	2056
1999-12-31	1715
2000-03-31	1512
2000-06-30	1238
2000-09-30	954
2000-12-31	897
2001-03-31	1191
2001-06-30	759
2001-09-30	750
2001-12-31	882
2002-03-31	1166
2002-06-30	1541
2002-09-30	1977
2002-12-31	1142
2003-03-31	1519
2003-06-30	1872
2003-09-30	2055
2003-12-31	1772
2004-03-31	1709
2004-06-30	2508
2004-09-30	2408
2004-12-31	2437
2005-03-31	1866
2005-06-30	1665
2005-09-30	1845
2005-12-31	1465
2006-03-31	1450
2006-06-30	1262
2006-09-30	1566
2006-12-31	1748
2007-03-31	2216
2007-06-30	1966
2007-09-30	1754
2007-12-31	2289
2008-03-31	2042
2008-06-30	2568
2008-09-30	2340
2008-12-31	1718
2009-03-31	1876
2009-06-30	1525
2009-09-30	1224
2009-12-31	2399
2010-03-31	2319
2010-06-30	2597
2010-09-30	2356
2010-12-31	2177
2011-03-31	2419
2011-06-30	2597
2011-09-30	2425
2011-12-31	1929
2012-03-31	2830
2012-06-30	2356
2012-09-30	2281
2012-12-31	2164
2013-03-31	3286
2013-06-30	1943
2013-09-30	2156
2013-12-31	2668
2014-03-31	1805
2014-06-30	1966
2014-09-30	2081
2014-12-31	2020
2015-03-31	1744
2015-06-30	1932
2015-09-30	2180
2015-12-31	2287
2016-03-31	2388
2016-06-30	2206
2016-09-30	2595
2016-12-31	2283
2017-03-31	2351
2017-06-30	3146
2017-09-30	3025
2017-12-31	2957
2018-03-31	2974
2018-06-30	2188
2018-09-30	4412
2018-12-31	3422
2019-03-31	4054
2019-06-30	4427
2019-09-30	4121
2019-12-31	4095
2020-03-31	3203
2020-06-30	3138
2020-09-30	3302
2020-12-31	3349
2021-03-31	3385
2021-06-30	4674
2021-09-30	4966
2021-12-31	4212
2022-03-31	4358
2022-06-30	3747
2022-09-30	5314
2022-12-31	4090
2023-03-31	4488
2023-06-30	4633
2023-09-30	4035