Bi-annual	US dollars
1987-06-30	556
1987-12-31	602
1988-06-30	607
1988-12-31	626
1989-06-30	637
1989-12-31	576
1990-06-30	506
1990-12-31	452
1991-06-30	444
1991-12-31	422
1992-06-30	413
1992-12-31	359
1993-06-30	324
1993-12-31	331
1994-06-30	307
1994-12-31	347
1995-06-30	388
1995-12-31	518
1996-06-30	541
1996-12-31	563
1997-06-30	612
1997-12-31	625
1998-06-30	637
1998-12-31	661
1999-06-30	593