Bi-annual US dollars 1987-06-30 34 1987-12-31 17 1988-06-30 9 1988-12-31 13 1989-06-30 31 1989-12-31 42 1990-06-30 26 1990-12-31 27 1991-06-30 21 1991-12-31 30 1992-06-30 23 1992-12-31 26 1993-06-30 24 1993-12-31 31 1994-06-30 29 1994-12-31 25 1995-06-30 29 1995-12-31 42 1996-06-30 67 1996-12-31 106 1997-06-30 100 1997-12-31 100 1998-06-30 95 1998-12-31 83 1999-06-30 57