Bi-annual US dollars 1987-06-30 29 1987-12-31 32 1988-06-30 17 1988-12-31 11 1989-06-30 17 1989-12-31 66 1990-06-30 75 1990-12-31 60 1991-06-30 60 1991-12-31 54 1992-06-30 67 1992-12-31 59 1993-06-30 18 1993-12-31 28 1994-06-30 15 1994-12-31 31 1995-06-30 0 1995-12-31 22 1996-06-30 17 1996-12-31 430 1997-06-30 534 1997-12-31 109 1998-06-30 67 1998-12-31 165 1999-06-30 35