Bi-annual US dollars 1987-06-30 124 1987-12-31 149 1988-06-30 135 1988-12-31 118 1989-06-30 132 1989-12-31 63 1990-06-30 80 1990-12-31 135 1991-06-30 57 1991-12-31 24 1992-06-30 86 1992-12-31 86 1993-06-30 47 1993-12-31 185 1994-06-30 153 1994-12-31 102 1995-06-30 121 1995-12-31 91 1996-06-30 56 1996-12-31 122 1997-06-30 148 1997-12-31 90 1998-06-30 310 1998-12-31 111 1999-06-30 240