Bi-annual US dollars 1987-06-30 69 1987-12-31 113 1988-06-30 77 1988-12-31 103 1989-06-30 57 1989-12-31 32 1990-06-30 51 1990-12-31 66 1991-06-30 66 1991-12-31 105 1992-06-30 116 1992-12-31 156 1993-06-30 156 1993-12-31 217 1994-06-30 230 1994-12-31 272 1995-06-30 243 1995-12-31 143 1996-06-30 152 1996-12-31 238 1997-06-30 155 1997-12-31 229 1998-06-30 98 1998-12-31 205 1999-06-30 147