Bi-annual US dollars 1987-06-30 66 1987-12-31 77 1988-06-30 60 1988-12-31 143 1989-06-30 62 1989-12-31 24 1990-06-30 5 1990-12-31 4 1991-06-30 15 1991-12-31 15 1992-06-30 11 1992-12-31 9 1993-06-30 0 1993-12-31 31 1994-06-30 17 1994-12-31 17 1995-06-30 19 1995-12-31 12 1996-06-30 16 1996-12-31 17 1997-06-30 37 1997-12-31 38 1998-06-30 57 1998-12-31 67 1999-06-30 88