Bi-annual	US dollars
1987-06-30	1700
1987-12-31	1544
1988-06-30	1315
1988-12-31	1501
1989-06-30	1539
1989-12-31	1513
1990-06-30	1298
1990-12-31	1279
1991-06-30	1206
1991-12-31	1515
1992-06-30	1543
1992-12-31	1463
1993-06-30	1142
1993-12-31	1073
1994-06-30	818
1994-12-31	774
1995-06-30	843
1995-12-31	805
1996-06-30	625
1996-12-31	875
1997-06-30	837
1997-12-31	1275
1998-06-30	1349
1998-12-31	1315
1999-06-30	1353