Bi-annual	US dollars
1987-06-30	1988
1987-12-31	1900
1988-06-30	1844
1988-12-31	1432
1989-06-30	2249
1989-12-31	2266
1990-06-30	1439
1990-12-31	1648
1991-06-30	1116
1991-12-31	1461
1992-06-30	2457
1992-12-31	2007
1993-06-30	2767
1993-12-31	3089
1994-06-30	2823
1994-12-31	1590
1995-06-30	2808
1995-12-31	3715
1996-06-30	2708
1996-12-31	1731
1997-06-30	2199
1997-12-31	1946
1998-06-30	1512
1998-12-31	3443
1999-06-30	2766