Bi-annual	US dollars
1987-06-30	637
1987-12-31	664
1988-06-30	623
1988-12-31	645
1989-06-30	524
1989-12-31	569
1990-06-30	520
1990-12-31	417
1991-06-30	378
1991-12-31	430
1992-06-30	407
1992-12-31	289
1993-06-30	438
1993-12-31	588
1994-06-30	323
1994-12-31	396
1995-06-30	358
1995-12-31	298
1996-06-30	370
1996-12-31	467
1997-06-30	526
1997-12-31	538
1998-06-30	647
1998-12-31	559
1999-06-30	695