Bi-annual US dollars 1987-06-30 339 1987-12-31 438 1988-06-30 517 1988-12-31 432 1989-06-30 493 1989-12-31 556 1990-06-30 555 1990-12-31 575 1991-06-30 671 1991-12-31 566 1992-06-30 657 1992-12-31 612 1993-06-30 1148 1993-12-31 1017 1994-06-30 1153 1994-12-31 1845 1995-06-30 1613 1995-12-31 1811 1996-06-30 1754 1996-12-31 1854 1997-06-30 2040 1997-12-31 2924 1998-06-30 2396 1998-12-31 2599 1999-06-30 2133