Bi-annual US dollars 1987-06-30 44 1987-12-31 11 1988-06-30 19 1988-12-31 9 1989-06-30 48 1989-12-31 79 1990-06-30 37 1990-12-31 44 1991-06-30 37 1991-12-31 77 1992-06-30 49 1992-12-31 58 1993-06-30 87 1993-12-31 251 1994-06-30 19 1994-12-31 33 1995-06-30 30 1995-12-31 65 1996-06-30 62 1996-12-31 84 1997-06-30 52 1997-12-31 43 1998-06-30 43 1998-12-31 13 1999-06-30 5