Bi-annual	US dollars
1987-06-30	21511
1987-12-31	22876
1988-06-30	22816
1988-12-31	23423
1989-06-30	22332
1989-12-31	17557
1990-06-30	15987
1990-12-31	16748
1991-06-30	15375
1991-12-31	15159
1992-06-30	14697
1992-12-31	13234
1993-06-30	13209
1993-12-31	12726
1994-06-30	12937
1994-12-31	12685
1995-06-30	12704
1995-12-31	12043
1996-06-30	11272
1996-12-31	11636
1997-06-30	11851
1997-12-31	11794
1998-06-30	12630
1998-12-31	13267
1999-06-30	12837