Bi-annual	US dollars
1987-06-30	11902
1987-12-31	10171
1988-06-30	10160
1988-12-31	9883
1989-06-30	8182
1989-12-31	7540
1990-06-30	6763
1990-12-31	5457
1991-06-30	6321
1991-12-31	6679
1992-06-30	9806
1992-12-31	8952
1993-06-30	11900
1993-12-31	12213
1994-06-30	14563
1994-12-31	14841
1995-06-30	14751
1995-12-31	15220
1996-06-30	16416
1996-12-31	18741
1997-06-30	18672
1997-12-31	20107
1998-06-30	22777
1998-12-31	20913
1999-06-30	21090