Bi-annual	US dollars
1987-06-30	806
1987-12-31	1081
1988-06-30	1223
1988-12-31	1546
1989-06-30	3719
1989-12-31	2175
1990-06-30	2060
1990-12-31	2227
1991-06-30	2020
1991-12-31	3543
1992-06-30	3260
1992-12-31	3010
1993-06-30	1313
1993-12-31	1978
1994-06-30	2738
1994-12-31	2497
1995-06-30	1541
1995-12-31	3099
1996-06-30	1866
1996-12-31	1556
1997-06-30	3693
1997-12-31	5239
1998-06-30	4402
1998-12-31	4729
1999-06-30	5505