Bi-annual	US dollars
1987-06-30	2103
1987-12-31	1900
1988-06-30	1748
1988-12-31	1461
1989-06-30	1511
1989-12-31	1985
1990-06-30	2110
1990-12-31	2736
1991-06-30	2414
1991-12-31	2019
1992-06-30	2658
1992-12-31	2289
1993-06-30	2738
1993-12-31	2589
1994-06-30	4255
1994-12-31	2911
1995-06-30	3432
1995-12-31	2931
1996-06-30	3155
1996-12-31	2330
1997-06-30	2805
1997-12-31	2047
1998-06-30	2498
1998-12-31	3022
1999-06-30	2781