Bi-annual	US dollars
1987-06-30	9330
1987-12-31	9705
1988-06-30	9131
1988-12-31	9516
1989-06-30	7838
1989-12-31	7929
1990-06-30	7018
1990-12-31	7365
1991-06-30	6306
1991-12-31	7043
1992-06-30	6721
1992-12-31	6171
1993-06-30	7444
1993-12-31	7405
1994-06-30	8236
1994-12-31	9115
1995-06-30	9099
1995-12-31	10309
1996-06-30	10129
1996-12-31	11256
1997-06-30	11599
1997-12-31	11631
1998-06-30	11416
1998-12-31	10769
1999-06-30	10080