Bi-annual US dollars 1987-06-30 3062 1987-12-31 3312 1988-06-30 3384 1988-12-31 3276 1989-06-30 3220 1989-12-31 2727 1990-06-30 2351 1990-12-31 2190 1991-06-30 2114 1991-12-31 2344 1992-06-30 2084 1992-12-31 2032 1993-06-30 788 1993-12-31 806 1994-06-30 835 1994-12-31 959 1995-06-30 1032 1995-12-31 1219 1996-06-30 1150 1996-12-31 1162 1997-06-30 1584 1997-12-31 3993 1998-06-30 4757 1998-12-31 5306 1999-06-30 5574