Bi-annual US dollars 1987-06-30 63 1987-12-31 70 1988-06-30 44 1988-12-31 13 1989-06-30 12 1989-12-31 16 1990-06-30 16 1990-12-31 25 1991-06-30 28 1991-12-31 37 1992-06-30 29 1992-12-31 29 1993-06-30 68 1993-12-31 64 1994-06-30 48 1994-12-31 42 1995-06-30 62 1995-12-31 33 1996-06-30 26 1996-12-31 63 1997-06-30 35 1997-12-31 61 1998-06-30 247 1998-12-31 423 1999-06-30 374