Bi-annual US dollars 1987-06-30 1791 1987-12-31 1929 1988-06-30 2395 1988-12-31 2732 1989-06-30 2589 1989-12-31 2067 1990-06-30 2040 1990-12-31 1729 1991-06-30 1602 1991-12-31 1591 1992-06-30 1532 1992-12-31 1385 1993-06-30 159 1993-12-31 340 1994-06-30 390 1994-12-31 329 1995-06-30 340 1995-12-31 282 1996-06-30 232 1996-12-31 130 1997-06-30 383 1997-12-31 987 1998-06-30 1004 1998-12-31 1018 1999-06-30 927