Quarter	US dollars
1999-03-31	54596
1999-06-30	54121
1999-09-30	52681
1999-12-31	48567
2000-03-31	51164
2000-06-30	48090
2000-09-30	46439
2000-12-31	47180
2001-03-31	45177
2001-06-30	45893
2001-09-30	44567
2001-12-31	39443
2002-03-31	44099
2002-06-30	46213
2002-09-30	46713
2002-12-31	45215
2003-03-31	51359
2003-06-30	48161
2003-09-30	54628
2003-12-31	60369
2004-03-31	72401
2004-06-30	71147
2004-09-30	79478
2004-12-31	80756
2005-03-31	96652
2005-06-30	86762
2005-09-30	103666
2005-12-31	97158
2006-03-31	125431
2006-06-30	119201
2006-09-30	134540
2006-12-31	114266
2007-03-31	145248
2007-06-30	157595
2007-09-30	167049
2007-12-31	179276
2008-03-31	208744
2008-06-30	180814
2008-09-30	182571
2008-12-31	140888
2009-03-31	125250
2009-06-30	137235
2009-09-30	129436
2009-12-31	135641
2010-03-31	148365
2010-06-30	159401
2010-09-30	171866
2010-12-31	173858
2011-03-31	206258
2011-06-30	213238
2011-09-30	196794
2011-12-31	200259
2012-03-31	207363
2012-06-30	193846
2012-09-30	199931
2012-12-31	210148
2013-03-31	240773
2013-06-30	249296
2013-09-30	248081
2013-12-31	236809
2014-03-31	263452
2014-06-30	255873
2014-09-30	248442
2014-12-31	234685
2015-03-31	234356
2015-06-30	241631
2015-09-30	226786
2015-12-31	225483
2016-03-31	210319
2016-06-30	208996
2016-09-30	205430
2016-12-31	203979
2017-03-31	212576
2017-06-30	210658
2017-09-30	226898
2017-12-31	237370
2018-03-31	241464
2018-06-30	227990
2018-09-30	235720
2018-12-31	237600
2019-03-31	246437
2019-06-30	244441
2019-09-30	232060
2019-12-31	244762
2020-03-31	236575
2020-06-30	211771
2020-09-30	214764
2020-12-31	232653
2021-03-31	239726
2021-06-30	234226
2021-09-30	234998
2021-12-31	271044
2022-03-31	261635
2022-06-30	253769
2022-09-30	280299
2022-12-31	264386
2023-03-31	259293
2023-06-30	256145
2023-09-30	245265