Bi-annual US dollars 1987-06-30 1575 1987-12-31 1796 1988-06-30 1499 1988-12-31 1275 1989-06-30 1859 1989-12-31 1645 1990-06-30 849 1990-12-31 722 1991-06-30 731 1991-12-31 742 1992-06-30 851 1992-12-31 732 1993-06-30 1395 1993-12-31 936 1994-06-30 991 1994-12-31 1355 1995-06-30 1351 1995-12-31 1405 1996-06-30 1128 1996-12-31 1168 1997-06-30 1236 1997-12-31 1185 1998-06-30 1267 1998-12-31 1165 1999-06-30 1714