Bi-annual US dollars 1987-06-30 163 1987-12-31 132 1988-06-30 138 1988-12-31 165 1989-06-30 152 1989-12-31 118 1990-06-30 152 1990-12-31 156 1991-06-30 88 1991-12-31 67 1992-06-30 63 1992-12-31 29 1993-06-30 53 1993-12-31 24 1994-06-30 14 1994-12-31 28 1995-06-30 14 1995-12-31 17 1996-06-30 92 1996-12-31 45 1997-06-30 60 1997-12-31 61 1998-06-30 0 1998-12-31 0 1999-06-30 0