Bi-annual	US dollars
1987-06-30	5107
1987-12-31	5246
1988-06-30	5359
1988-12-31	4527
1989-06-30	4269
1989-12-31	4741
1990-06-30	5377
1990-12-31	5783
1991-06-30	4582
1991-12-31	4922
1992-06-30	5209
1992-12-31	5049
1993-06-30	13132
1993-12-31	13895
1994-06-30	13734
1994-12-31	12899
1995-06-30	16043
1995-12-31	18645
1996-06-30	17756
1996-12-31	19183
1997-06-30	21008
1997-12-31	20961
1998-06-30	17643
1998-12-31	17762
1999-06-30	15541