Quarter	US dollars
1999-03-31	4386
1999-06-30	4299
1999-09-30	3999
1999-12-31	4282
2000-03-31	4297
2000-06-30	3898
2000-09-30	4063
2000-12-31	4060
2001-03-31	4506
2001-06-30	3598
2001-09-30	4375
2001-12-31	3749
2002-03-31	3482
2002-06-30	3591
2002-09-30	3190
2002-12-31	3703
2003-03-31	3696
2003-06-30	3675
2003-09-30	4566
2003-12-31	3113
2004-03-31	3676
2004-06-30	3881
2004-09-30	3986
2004-12-31	4518
2005-03-31	4281
2005-06-30	5043
2005-09-30	5021
2005-12-31	6093
2006-03-31	7160
2006-06-30	6909
2006-09-30	7783
2006-12-31	7891
2007-03-31	7937
2007-06-30	7677
2007-09-30	8150
2007-12-31	10922
2008-03-31	10638
2008-06-30	10660
2008-09-30	11127
2008-12-31	12439
2009-03-31	10075
2009-06-30	9483
2009-09-30	9545
2009-12-31	7845
2010-03-31	7456
2010-06-30	6926
2010-09-30	8142
2010-12-31	8671
2011-03-31	8016
2011-06-30	6759
2011-09-30	7175
2011-12-31	6283
2012-03-31	7150
2012-06-30	7004
2012-09-30	6423
2012-12-31	7323
2013-03-31	6198
2013-06-30	7168
2013-09-30	6349
2013-12-31	7588
2014-03-31	8026
2014-06-30	8766
2014-09-30	8332
2014-12-31	9600
2015-03-31	9888
2015-06-30	8529
2015-09-30	8828
2015-12-31	8936
2016-03-31	7275
2016-06-30	6832
2016-09-30	7181
2016-12-31	6878
2017-03-31	6733
2017-06-30	6573
2017-09-30	7233
2017-12-31	8295
2018-03-31	8227
2018-06-30	8233
2018-09-30	6144
2018-12-31	8134
2019-03-31	7439
2019-06-30	8112
2019-09-30	7108
2019-12-31	8377
2020-03-31	6934
2020-06-30	6722
2020-09-30	6723
2020-12-31	6212
2021-03-31	5401
2021-06-30	4756
2021-09-30	4249
2021-12-31	4369
2022-03-31	4576
2022-06-30	6235
2022-09-30	5760
2022-12-31	7623
2023-03-31	5723
2023-06-30	6192
2023-09-30	6656