Quarter	US dollars
1999-03-31	38199
1999-06-30	31320
1999-09-30	28785
1999-12-31	26783
2000-03-31	28710
2000-06-30	25092
2000-09-30	24021
2000-12-31	24683
2001-03-31	27063
2001-06-30	26663
2001-09-30	27876
2001-12-31	28169
2002-03-31	26368
2002-06-30	30898
2002-09-30	32773
2002-12-31	31327
2003-03-31	34821
2003-06-30	37759
2003-09-30	44730
2003-12-31	71567
2004-03-31	83411
2004-06-30	98494
2004-09-30	102799
2004-12-31	104896
2005-03-31	109196
2005-06-30	119922
2005-09-30	133889
2005-12-31	135301
2006-03-31	137731
2006-06-30	128434
2006-09-30	139834
2006-12-31	151751
2007-03-31	152065
2007-06-30	157125
2007-09-30	164177
2007-12-31	172435
2008-03-31	235725
2008-06-30	227905
2008-09-30	210753
2008-12-31	206798
2009-03-31	232590
2009-06-30	239821
2009-09-30	226191
2009-12-31	224630
2010-03-31	214778
2010-06-30	186023
2010-09-30	200979
2010-12-31	180546
2011-03-31	192477
2011-06-30	206403
2011-09-30	170197
2011-12-31	152291
2012-03-31	147112
2012-06-30	149969
2012-09-30	141881
2012-12-31	142322
2013-03-31	137453
2013-06-30	133147
2013-09-30	87871
2013-12-31	88480
2014-03-31	81163
2014-06-30	75815
2014-09-30	67659
2014-12-31	35696
2015-03-31	34317
2015-06-30	31216
2015-09-30	30852
2015-12-31	28141
2016-03-31	29141
2016-06-30	30897
2016-09-30	26177
2016-12-31	22319
2017-03-31	25581
2017-06-30	26777
2017-09-30	28008
2017-12-31	32037
2018-03-31	30045
2018-06-30	30353
2018-09-30	25329
2018-12-31	24527
2019-03-31	17454
2019-06-30	15592
2019-09-30	15741
2019-12-31	15102
2020-03-31	19081
2020-06-30	17866
2020-09-30	15241
2020-12-31	17667
2021-03-31	13258
2021-06-30	10463
2021-09-30	16392
2021-12-31	19010
2022-03-31	19090
2022-06-30	20466
2022-09-30	21924
2022-12-31	24359
2023-03-31	27050
2023-06-30	32853
2023-09-30	29327