Bi-annual	US dollars
1987-06-30	2640
1987-12-31	2563
1988-06-30	2403
1988-12-31	2334
1989-06-30	2173
1989-12-31	2080
1990-06-30	1913
1990-12-31	1084
1991-06-30	1550
1991-12-31	1903
1992-06-30	2168
1992-12-31	2098
1993-06-30	1859
1993-12-31	1528
1994-06-30	1205
1994-12-31	1008
1995-06-30	857
1995-12-31	831
1996-06-30	760
1996-12-31	800
1997-06-30	645
1997-12-31	788
1998-06-30	1479
1998-12-31	912
1999-06-30	1015