Bi-annual US dollars 1987-06-30 242 1987-12-31 238 1988-06-30 423 1988-12-31 362 1989-06-30 415 1989-12-31 284 1990-06-30 190 1990-12-31 257 1991-06-30 230 1991-12-31 245 1992-06-30 238 1992-12-31 1444 1993-06-30 2116 1993-12-31 2579 1994-06-30 1434 1994-12-31 2284 1995-06-30 2235 1995-12-31 2819 1996-06-30 3665 1996-12-31 5162 1997-06-30 5380 1997-12-31 5388 1998-06-30 6723 1998-12-31 6307 1999-06-30 5159