Bi-annual	US dollars
1987-06-30	2058
1987-12-31	2493
1988-06-30	2700
1988-12-31	2569
1989-06-30	2941
1989-12-31	2643
1990-06-30	2879
1990-12-31	3361
1991-06-30	2888
1991-12-31	3872
1992-06-30	3886
1992-12-31	2488
1993-06-30	2255
1993-12-31	1587
1994-06-30	1883
1994-12-31	1981
1995-06-30	1955
1995-12-31	1477
1996-06-30	1585
1996-12-31	1578
1997-06-30	1511
1997-12-31	1836
1998-06-30	1744
1998-12-31	2062
1999-06-30	1993