Bi-annual US dollars 1987-06-30 127 1987-12-31 181 1988-06-30 145 1988-12-31 163 1989-06-30 122 1989-12-31 158 1990-06-30 89 1990-12-31 93 1991-06-30 79 1991-12-31 97 1992-06-30 74 1992-12-31 33 1993-06-30 60 1993-12-31 115 1994-06-30 88 1994-12-31 75 1995-06-30 78 1995-12-31 64 1996-06-30 176 1996-12-31 255 1997-06-30 178 1997-12-31 132 1998-06-30 115 1998-12-31 133 1999-06-30 44