Bi-annual US dollars 1987-06-30 68 1987-12-31 42 1988-06-30 36 1988-12-31 33 1989-06-30 31 1989-12-31 35 1990-06-30 30 1990-12-31 15 1991-06-30 18 1991-12-31 15 1992-06-30 11 1992-12-31 14 1993-06-30 93 1993-12-31 86 1994-06-30 93 1994-12-31 91 1995-06-30 94 1995-12-31 91 1996-06-30 81 1996-12-31 140 1997-06-30 163 1997-12-31 189 1998-06-30 170 1998-12-31 369 1999-06-30 399