Bi-annual	US dollars
1987-06-30	7674
1987-12-31	10165
1988-06-30	9321
1988-12-31	9167
1989-06-30	9830
1989-12-31	10047
1990-06-30	9541
1990-12-31	10680
1991-06-30	9812
1991-12-31	10482
1992-06-30	9738
1992-12-31	8979
1993-06-30	13384
1993-12-31	14360
1994-06-30	15750
1994-12-31	21039
1995-06-30	19542
1995-12-31	17669
1996-06-30	19060
1996-12-31	18796
1997-06-30	21981
1997-12-31	15273
1998-06-30	12728
1998-12-31	13154
1999-06-30	12572