Bi-annual	US dollars
1987-06-30	2665
1987-12-31	3323
1988-06-30	1097
1988-12-31	1334
1989-06-30	811
1989-12-31	1076
1990-06-30	928
1990-12-31	712
1991-06-30	1211
1991-12-31	1834
1992-06-30	1648
1992-12-31	1757
1993-06-30	4476
1993-12-31	6177
1994-06-30	2333
1994-12-31	17562
1995-06-30	23442
1995-12-31	26438
1996-06-30	29769
1996-12-31	39626
1997-06-30	41835
1997-12-31	45150
1998-06-30	47588
1998-12-31	57440
1999-06-30	55070