Bi-annual US dollars 1987-06-30 1017 1987-12-31 732 1988-06-30 508 1988-12-31 360 1989-06-30 425 1989-12-31 248 1990-06-30 204 1990-12-31 417 1991-06-30 413 1991-12-31 527 1992-06-30 514 1992-12-31 620 1993-06-30 1026 1993-12-31 1011 1994-06-30 1378 1994-12-31 1015 1995-06-30 1026 1995-12-31 1158 1996-06-30 1229 1996-12-31 1418 1997-06-30 2011 1997-12-31 2004 1998-06-30 1614 1998-12-31 2010 1999-06-30 2051