Bi-annual US dollars 1987-06-30 8166 1987-12-31 13094 1988-06-30 10888 1988-12-31 15674 1989-06-30 9259 1989-12-31 10805 1990-06-30 11418 1990-12-31 14282 1991-06-30 10233 1991-12-31 13159 1992-06-30 7757 1992-12-31 6927 1993-06-30 8592 1993-12-31 7316 1994-06-30 7986 1994-12-31 7976 1995-06-30 8655 1995-12-31 9587 1996-06-30 10764 1996-12-31 14450 1997-06-30 12316 1997-12-31 14520 1998-06-30 13839 1998-12-31 13084 1999-06-30 13195