Bi-annual US dollars 1987-06-30 74 1987-12-31 83 1988-06-30 97 1988-12-31 103 1989-06-30 177 1989-12-31 127 1990-06-30 75 1990-12-31 83 1991-06-30 50 1991-12-31 56 1992-06-30 126 1992-12-31 189 1993-06-30 191 1993-12-31 64 1994-06-30 85 1994-12-31 30 1995-06-30 22 1995-12-31 20 1996-06-30 20 1996-12-31 21 1997-06-30 40 1997-12-31 5 1998-06-30 8 1998-12-31 7 1999-06-30 8