Bi-annual	US dollars
1987-06-30	2469
1987-12-31	3295
1988-06-30	2881
1988-12-31	2470
1989-06-30	2601
1989-12-31	2593
1990-06-30	3118
1990-12-31	2381
1991-06-30	1865
1991-12-31	2034
1992-06-30	1298
1992-12-31	1933
1993-06-30	2782
1993-12-31	2937
1994-06-30	4529
1994-12-31	2398
1995-06-30	3897
1995-12-31	4210
1996-06-30	3300
1996-12-31	3816
1997-06-30	2663
1997-12-31	4029
1998-06-30	2086
1998-12-31	2950
1999-06-30	2367