Bi-annual US dollars 1987-06-30 148 1987-12-31 117 1988-06-30 126 1988-12-31 110 1989-06-30 119 1989-12-31 76 1990-06-30 164 1990-12-31 123 1991-06-30 71 1991-12-31 56 1992-06-30 95 1992-12-31 136 1993-06-30 144 1993-12-31 152 1994-06-30 116 1994-12-31 116 1995-06-30 170 1995-12-31 87 1996-06-30 124 1996-12-31 142 1997-06-30 190 1997-12-31 240 1998-06-30 305 1998-12-31 250 1999-06-30 218