Bi-annual	US dollars
1987-06-30	4686
1987-12-31	5352
1988-06-30	5333
1988-12-31	4873
1989-06-30	5565
1989-12-31	5894
1990-06-30	6439
1990-12-31	8220
1991-06-30	7227
1991-12-31	8347
1992-06-30	9176
1992-12-31	8289
1993-06-30	9992
1993-12-31	9131
1994-06-30	10106
1994-12-31	17342
1995-06-30	15841
1995-12-31	15001
1996-06-30	16326
1996-12-31	18888
1997-06-30	17403
1997-12-31	18220
1998-06-30	21338
1998-12-31	18675
1999-06-30	17640