Bi-annual	US dollars
1987-06-30	1751
1987-12-31	2210
1988-06-30	2231
1988-12-31	2048
1989-06-30	2238
1989-12-31	2303
1990-06-30	1709
1990-12-31	1916
1991-06-30	1388
1991-12-31	1526
1992-06-30	1673
1992-12-31	1965
1993-06-30	2390
1993-12-31	2261
1994-06-30	3460
1994-12-31	2888
1995-06-30	3985
1995-12-31	3037
1996-06-30	2118
1996-12-31	2772
1997-06-30	2575
1997-12-31	2784
1998-06-30	2791
1998-12-31	3301
1999-06-30	2953