Quarter	US dollars
1999-03-31	7268
1999-06-30	7703
1999-09-30	8103
1999-12-31	8332
2000-03-31	7480
2000-06-30	7639
2000-09-30	7616
2000-12-31	7552
2001-03-31	7739
2001-06-30	7970
2001-09-30	8662
2001-12-31	8906
2002-03-31	7644
2002-06-30	7694
2002-09-30	7760
2002-12-31	7529
2003-03-31	7827
2003-06-30	8242
2003-09-30	7979
2003-12-31	7730
2004-03-31	9662
2004-06-30	10693
2004-09-30	10235
2004-12-31	10500
2005-03-31	11182
2005-06-30	10708
2005-09-30	12472
2005-12-31	13077
2006-03-31	12855
2006-06-30	15072
2006-09-30	15893
2006-12-31	15514
2007-03-31	16823
2007-06-30	16653
2007-09-30	21275
2007-12-31	18184
2008-03-31	20787
2008-06-30	19518
2008-09-30	17947
2008-12-31	15948
2009-03-31	14924
2009-06-30	14768
2009-09-30	20035
2009-12-31	18395
2010-03-31	14360
2010-06-30	13686
2010-09-30	14288
2010-12-31	13684
2011-03-31	13826
2011-06-30	14718
2011-09-30	15378
2011-12-31	12706
2012-03-31	14804
2012-06-30	15034
2012-09-30	14590
2012-12-31	16036
2013-03-31	18070
2013-06-30	15858
2013-09-30	15456
2013-12-31	15823
2014-03-31	14835
2014-06-30	14451
2014-09-30	14127
2014-12-31	14201
2015-03-31	14216
2015-06-30	16101
2015-09-30	15858
2015-12-31	15897
2016-03-31	16643
2016-06-30	18956
2016-09-30	19672
2016-12-31	18145
2017-03-31	18215
2017-06-30	17087
2017-09-30	17936
2017-12-31	18209
2018-03-31	18642
2018-06-30	17914
2018-09-30	15793
2018-12-31	16134
2019-03-31	15526
2019-06-30	15406
2019-09-30	16306
2019-12-31	16669
2020-03-31	17760
2020-06-30	18967
2020-09-30	16761
2020-12-31	16388
2021-03-31	17766
2021-06-30	17516
2021-09-30	18489
2021-12-31	17415
2022-03-31	15236
2022-06-30	14932
2022-09-30	14889
2022-12-31	13739
2023-03-31	12965
2023-06-30	13637
2023-09-30	14614