Bi-annual	US dollars
1987-06-30	1103
1987-12-31	1396
1988-06-30	1412
1988-12-31	1544
1989-06-30	1299
1989-12-31	1345
1990-06-30	1127
1990-12-31	978
1991-06-30	1049
1991-12-31	1784
1992-06-30	2364
1992-12-31	2024
1993-06-30	2420
1993-12-31	1932
1994-06-30	1937
1994-12-31	1815
1995-06-30	2482
1995-12-31	2833
1996-06-30	3570
1996-12-31	3323
1997-06-30	2945
1997-12-31	3111
1998-06-30	3105
1998-12-31	3584
1999-06-30	2875