Bi-annual	US dollars
1987-06-30	1508
1987-12-31	1787
1988-06-30	1907
1988-12-31	2133
1989-06-30	2096
1989-12-31	2080
1990-06-30	1990
1990-12-31	2090
1991-06-30	2067
1991-12-31	1980
1992-06-30	1886
1992-12-31	1857
1993-06-30	7046
1993-12-31	8475
1994-06-30	9421
1994-12-31	10147
1995-06-30	11245
1995-12-31	12559
1996-06-30	12663
1996-12-31	13669
1997-06-30	16050
1997-12-31	21450
1998-06-30	20173
1998-12-31	18743
1999-06-30	17517