Bi-annual US dollars 1987-06-30 37 1987-12-31 66 1988-06-30 72 1988-12-31 34 1989-06-30 39 1989-12-31 56 1990-06-30 37 1990-12-31 27 1991-06-30 54 1991-12-31 26 1992-06-30 30 1992-12-31 32 1993-06-30 59 1993-12-31 78 1994-06-30 173 1994-12-31 189 1995-06-30 143 1995-12-31 102 1996-06-30 143 1996-12-31 146 1997-06-30 138 1997-12-31 161 1998-06-30 250 1998-12-31 358 1999-06-30 341