Quarter	US dollars
1999-03-31	16034
1999-06-30	15643
1999-09-30	12095
1999-12-31	6875
2000-03-31	8649
2000-06-30	9082
2000-09-30	6562
2000-12-31	7044
2001-03-31	9840
2001-06-30	10545
2001-09-30	9060
2001-12-31	7942
2002-03-31	8633
2002-06-30	11263
2002-09-30	11529
2002-12-31	11504
2003-03-31	14153
2003-06-30	17804
2003-09-30	14448
2003-12-31	17141
2004-03-31	20530
2004-06-30	16911
2004-09-30	19769
2004-12-31	24764
2005-03-31	19546
2005-06-30	17931
2005-09-30	20934
2005-12-31	16172
2006-03-31	16584
2006-06-30	15106
2006-09-30	21993
2006-12-31	22596
2007-03-31	20687
2007-06-30	18681
2007-09-30	19323
2007-12-31	19329
2008-03-31	20059
2008-06-30	17939
2008-09-30	19872
2008-12-31	18587
2009-03-31	19398
2009-06-30	19716
2009-09-30	21489
2009-12-31	26917
2010-03-31	18387
2010-06-30	15136
2010-09-30	17968
2010-12-31	16843
2011-03-31	17225
2011-06-30	16913
2011-09-30	16668
2011-12-31	16115
2012-03-31	28128
2012-06-30	27664
2012-09-30	26759
2012-12-31	29351
2013-03-31	32756
2013-06-30	25470
2013-09-30	25738
2013-12-31	28679
2014-03-31	27301
2014-06-30	25479
2014-09-30	24900
2014-12-31	24223
2015-03-31	22508
2015-06-30	23285
2015-09-30	21302
2015-12-31	19254
2016-03-31	21606
2016-06-30	19596
2016-09-30	20955
2016-12-31	18595
2017-03-31	17101
2017-06-30	18676
2017-09-30	19235
2017-12-31	21701
2018-03-31	18967
2018-06-30	20245
2018-09-30	22142
2018-12-31	18734
2019-03-31	19559
2019-06-30	21410
2019-09-30	16686
2019-12-31	16271
2020-03-31	16544
2020-06-30	18117
2020-09-30	17017
2020-12-31	21655
2021-03-31	16622
2021-06-30	16679
2021-09-30	15729
2021-12-31	14346
2022-03-31	14826
2022-06-30	10596
2022-09-30	11143
2022-12-31	13230
2023-03-31	11794
2023-06-30	12772
2023-09-30	9835