Bi-annual	US dollars
1987-06-30	1588
1987-12-31	1893
1988-06-30	1678
1988-12-31	1926
1989-06-30	2063
1989-12-31	2133
1990-06-30	1873
1990-12-31	2078
1991-06-30	1553
1991-12-31	2193
1992-06-30	1975
1992-12-31	2024
1993-06-30	1934
1993-12-31	1726
1994-06-30	1520
1994-12-31	1910
1995-06-30	1779
1995-12-31	1563
1996-06-30	1812
1996-12-31	1739
1997-06-30	2569
1997-12-31	2934
1998-06-30	4158
1998-12-31	3015
1999-06-30	3202