Bi-annual US dollars 1987-06-30 139 1987-12-31 72 1988-06-30 46 1988-12-31 94 1989-06-30 59 1989-12-31 121 1990-06-30 105 1990-12-31 95 1991-06-30 71 1991-12-31 86 1992-06-30 126 1992-12-31 147 1993-06-30 239 1993-12-31 213 1994-06-30 204 1994-12-31 131 1995-06-30 142 1995-12-31 144 1996-06-30 163 1996-12-31 200 1997-06-30 536 1997-12-31 480 1998-06-30 852 1998-12-31 810 1999-06-30 1988