Bi-annual US dollars 1987-06-30 94 1987-12-31 125 1988-06-30 126 1988-12-31 226 1989-06-30 251 1989-12-31 181 1990-06-30 180 1990-12-31 224 1991-06-30 225 1991-12-31 179 1992-06-30 183 1992-12-31 153 1993-06-30 302 1993-12-31 705 1994-06-30 1056 1994-12-31 1381 1995-06-30 1001 1995-12-31 1124 1996-06-30 1282 1996-12-31 1317 1997-06-30 1348 1997-12-31 1451 1998-06-30 1874 1998-12-31 1824 1999-06-30 1660