Bi-annual US dollars 1987-06-30 23 1987-12-31 28 1988-06-30 29 1988-12-31 34 1989-06-30 31 1989-12-31 32 1990-06-30 19 1990-12-31 10 1991-06-30 13 1991-12-31 24 1992-06-30 86 1992-12-31 79 1993-06-30 77 1993-12-31 87 1994-06-30 60 1994-12-31 13 1995-06-30 17 1995-12-31 31 1996-06-30 31 1996-12-31 29 1997-06-30 47 1997-12-31 39 1998-06-30 52 1998-12-31 20 1999-06-30 16