Bi-annual US dollars 1987-06-30 77 1987-12-31 53 1988-06-30 109 1988-12-31 13 1989-06-30 96 1989-12-31 5 1990-06-30 42 1990-12-31 39 1991-06-30 23 1991-12-31 32 1992-06-30 42 1992-12-31 97 1993-06-30 35 1993-12-31 105 1994-06-30 63 1994-12-31 186 1995-06-30 81 1995-12-31 99 1996-06-30 36 1996-12-31 94 1997-06-30 100 1997-12-31 151 1998-06-30 77 1998-12-31 131 1999-06-30 60