Bi-annual US dollars 1987-06-30 69 1987-12-31 319 1988-06-30 96 1988-12-31 52 1989-06-30 56 1989-12-31 53 1990-06-30 129 1990-12-31 141 1991-06-30 36 1991-12-31 86 1992-06-30 167 1992-12-31 138 1993-06-30 132 1993-12-31 49 1994-06-30 68 1994-12-31 97 1995-06-30 68 1995-12-31 39 1996-06-30 48 1996-12-31 39 1997-06-30 133 1997-12-31 90 1998-06-30 87 1998-12-31 92 1999-06-30 115