Bi-annual	US dollars
1987-06-30	8737
1987-12-31	8597
1988-06-30	8695
1988-12-31	9065
1989-06-30	7013
1989-12-31	6631
1990-06-30	5745
1990-12-31	6024
1991-06-30	5714
1991-12-31	6364
1992-06-30	7740
1992-12-31	6034
1993-06-30	8391
1993-12-31	8651
1994-06-30	8847
1994-12-31	8478
1995-06-30	9495
1995-12-31	10602
1996-06-30	11650
1996-12-31	15014
1997-06-30	11337
1997-12-31	12124
1998-06-30	11241
1998-12-31	13575
1999-06-30	12745