Quarter	US dollars
1999-03-31	13708
1999-06-30	9767
1999-09-30	10911
1999-12-31	11945
2000-03-31	10024
2000-06-30	9673
2000-09-30	14481
2000-12-31	17783
2001-03-31	21452
2001-06-30	20825
2001-09-30	17451
2001-12-31	12786
2002-03-31	9801
2002-06-30	9601
2002-09-30	11117
2002-12-31	14619
2003-03-31	19814
2003-06-30	10600
2003-09-30	12629
2003-12-31	14066
2004-03-31	20423
2004-06-30	21682
2004-09-30	33027
2004-12-31	19176
2005-03-31	15848
2005-06-30	21810
2005-09-30	23857
2005-12-31	28206
2006-03-31	28079
2006-06-30	25445
2006-09-30	33750
2006-12-31	34638
2007-03-31	29485
2007-06-30	23245
2007-09-30	36244
2007-12-31	69982
2008-03-31	80304
2008-06-30	63729
2008-09-30	83673
2008-12-31	85911
2009-03-31	65209
2009-06-30	59084
2009-09-30	62738
2009-12-31	70990
2010-03-31	61981
2010-06-30	55678
2010-09-30	48499
2010-12-31	56099
2011-03-31	59180
2011-06-30	69244
2011-09-30	75720
2011-12-31	81119
2012-03-31	96322
2012-06-30	105849
2012-09-30	84203
2012-12-31	84185
2013-03-31	81420
2013-06-30	71555
2013-09-30	79810
2013-12-31	92251
2014-03-31	89930
2014-06-30	82817
2014-09-30	84649
2014-12-31	77178
2015-03-31	70472
2015-06-30	79965
2015-09-30	90957
2015-12-31	88887
2016-03-31	78531
2016-06-30	77076
2016-09-30	66213
2016-12-31	67663
2017-03-31	78248
2017-06-30	82456
2017-09-30	76984
2017-12-31	74716
2018-03-31	75042
2018-06-30	73943
2018-09-30	69675
2018-12-31	62925
2019-03-31	64632
2019-06-30	79886
2019-09-30	69702
2019-12-31	69283
2020-03-31	62827
2020-06-30	55713
2020-09-30	52256
2020-12-31	43360
2021-03-31	50156
2021-06-30	42129
2021-09-30	46186
2021-12-31	37429
2022-03-31	41889
2022-06-30	53137
2022-09-30	47103
2022-12-31	30526
2023-03-31	37631
2023-06-30	57910
2023-09-30	46932