Bi-annual US dollars 1987-06-30 390 1987-12-31 313 1988-06-30 256 1988-12-31 307 1989-06-30 195 1989-12-31 237 1990-06-30 180 1990-12-31 235 1991-06-30 305 1991-12-31 215 1992-06-30 483 1992-12-31 536 1993-06-30 846 1993-12-31 1212 1994-06-30 1028 1994-12-31 931 1995-06-30 1136 1995-12-31 1265 1996-06-30 1544 1996-12-31 1630 1997-06-30 1970 1997-12-31 2483 1998-06-30 2137 1998-12-31 2045 1999-06-30 1848