Quarter	US dollars
1999-03-31	39436
1999-06-30	38929
1999-09-30	38550
1999-12-31	37849
2000-03-31	35848
2000-06-30	35896
2000-09-30	35247
2000-12-31	36766
2001-03-31	35636
2001-06-30	35362
2001-09-30	35400
2001-12-31	33964
2002-03-31	33896
2002-06-30	37102
2002-09-30	35759
2002-12-31	37720
2003-03-31	39142
2003-06-30	38414
2003-09-30	39978
2003-12-31	42309
2004-03-31	44073
2004-06-30	43762
2004-09-30	47527
2004-12-31	52373
2005-03-31	50027
2005-06-30	51580
2005-09-30	53153
2005-12-31	59139
2006-03-31	66226
2006-06-30	64772
2006-09-30	70074
2006-12-31	75715
2007-03-31	76408
2007-06-30	89572
2007-09-30	96864
2007-12-31	118892
2008-03-31	128368
2008-06-30	127457
2008-09-30	130327
2008-12-31	130944
2009-03-31	122302
2009-06-30	121425
2009-09-30	119131
2009-12-31	116489
2010-03-31	119553
2010-06-30	123903
2010-09-30	122133
2010-12-31	127446
2011-03-31	128246
2011-06-30	127115
2011-09-30	122663
2011-12-31	126657
2012-03-31	130475
2012-06-30	126976
2012-09-30	134280
2012-12-31	136731
2013-03-31	128682
2013-06-30	124032
2013-09-30	131181
2013-12-31	121695
2014-03-31	140141
2014-06-30	134821
2014-09-30	141973
2014-12-31	146214
2015-03-31	146719
2015-06-30	155656
2015-09-30	157660
2015-12-31	169553
2016-03-31	159547
2016-06-30	164784
2016-09-30	168147
2016-12-31	166529
2017-03-31	169137
2017-06-30	166331
2017-09-30	174766
2017-12-31	188585
2018-03-31	205118
2018-06-30	194932
2018-09-30	193505
2018-12-31	196376
2019-03-31	210416
2019-06-30	219172
2019-09-30	215756
2019-12-31	229831
2020-03-31	220450
2020-06-30	213948
2020-09-30	218599
2020-12-31	232711
2021-03-31	232186
2021-06-30	230233
2021-09-30	223633
2021-12-31	232708
2022-03-31	231135
2022-06-30	227794
2022-09-30	223916
2022-12-31	223906
2023-03-31	216984
2023-06-30	219335
2023-09-30	215405