Bi-annual US dollars 1987-06-30 169 1987-12-31 226 1988-06-30 147 1988-12-31 76 1989-06-30 79 1989-12-31 74 1990-06-30 75 1990-12-31 79 1991-06-30 81 1991-12-31 118 1992-06-30 110 1992-12-31 74 1993-06-30 102 1993-12-31 167 1994-06-30 176 1994-12-31 239 1995-06-30 227 1995-12-31 192 1996-06-30 144 1996-12-31 181 1997-06-30 238 1997-12-31 551 1998-06-30 525 1998-12-31 45 1999-06-30 758