Bi-annual	US dollars
1987-06-30	6664
1987-12-31	5874
1988-06-30	6788
1988-12-31	4977
1989-06-30	5575
1989-12-31	5781
1990-06-30	5026
1990-12-31	5300
1991-06-30	4216
1991-12-31	4526
1992-06-30	4352
1992-12-31	3980
1993-06-30	9063
1993-12-31	7590
1994-06-30	8315
1994-12-31	8160
1995-06-30	7983
1995-12-31	8660
1996-06-30	11455
1996-12-31	12362
1997-06-30	13577
1997-12-31	12285
1998-06-30	12521
1998-12-31	9332
1999-06-30	8157