Bi-annual	US dollars
1987-06-30	2233
1987-12-31	2521
1988-06-30	2555
1988-12-31	2443
1989-06-30	2859
1989-12-31	2516
1990-06-30	2105
1990-12-31	2470
1991-06-30	1811
1991-12-31	1972
1992-06-30	2364
1992-12-31	2753
1993-06-30	2759
1993-12-31	2836
1994-06-30	4122
1994-12-31	3863
1995-06-30	4965
1995-12-31	4360
1996-06-30	3075
1996-12-31	3321
1997-06-30	3369
1997-12-31	3639
1998-06-30	4090
1998-12-31	4985
1999-06-30	3844