Bi-annual US dollars 1987-06-30 5536 1987-12-31 6267 1988-06-30 6232 1988-12-31 6939 1989-06-30 6438 1989-12-31 9011 1990-06-30 8369 1990-12-31 9071 1991-06-30 7465 1991-12-31 8213 1992-06-30 7347 1992-12-31 7872 1993-06-30 11689 1993-12-31 12903 1994-06-30 12565 1994-12-31 14802 1995-06-30 14904 1995-12-31 12244 1996-06-30 13783 1996-12-31 12177 1997-06-30 1319 1997-12-31 13177 1998-06-30 13902 1998-12-31 16221 1999-06-30 15356