Bi-annual US dollars 1987-06-30 34 1987-12-31 9 1988-06-30 7 1988-12-31 11 1989-06-30 14 1989-12-31 16 1990-06-30 21 1990-12-31 17 1991-06-30 16 1991-12-31 13 1992-06-30 30 1992-12-31 29 1993-06-30 110 1993-12-31 69 1994-06-30 82 1994-12-31 103 1995-06-30 3 1995-12-31 169 1996-06-30 11 1996-12-31 0 1997-06-30 10 1997-12-31 30 1998-06-30 195 1998-12-31 0 1999-06-30 0