Bi-annual US dollars 1987-06-30 34 1987-12-31 60 1988-06-30 29 1988-12-31 36 1989-06-30 25 1989-12-31 39 1990-06-30 65 1990-12-31 96 1991-06-30 60 1991-12-31 90 1992-06-30 59 1992-12-31 52 1993-06-30 41 1993-12-31 75 1994-06-30 105 1994-12-31 77 1995-06-30 62 1995-12-31 60 1996-06-30 179 1996-12-31 74 1997-06-30 53 1997-12-31 41 1998-06-30 32 1998-12-31 22 1999-06-30 32