Bi-annual	US dollars
1987-06-30	3280
1987-12-31	3427
1988-06-30	3184
1988-12-31	3475
1989-06-30	2995
1989-12-31	2978
1990-06-30	2679
1990-12-31	2778
1991-06-30	1931
1991-12-31	2032
1992-06-30	2240
1992-12-31	2004
1993-06-30	2717
1993-12-31	3504
1994-06-30	3438
1994-12-31	4571
1995-06-30	4362
1995-12-31	4282
1996-06-30	4341
1996-12-31	4634
1997-06-30	4997
1997-12-31	5719
1998-06-30	6442
1998-12-31	7460
1999-06-30	7430