Bi-annual US dollars 1987-06-30 40 1987-12-31 42 1988-06-30 46 1988-12-31 43 1989-06-30 39 1989-12-31 48 1990-06-30 129 1990-12-31 54 1991-06-30 60 1991-12-31 49 1992-06-30 57 1992-12-31 50 1993-06-30 54 1993-12-31 83 1994-06-30 74 1994-12-31 55 1995-06-30 59 1995-12-31 59 1996-06-30 31 1996-12-31 53 1997-06-30 72 1997-12-31 123 1998-06-30 75 1998-12-31 62 1999-06-30 38