Bi-annual	US dollars
1987-06-30	1909
1987-12-31	1491
1988-06-30	1173
1988-12-31	1106
1989-06-30	859
1989-12-31	1226
1990-06-30	984
1990-12-31	849
1991-06-30	1117
1991-12-31	1246
1992-06-30	1401
1992-12-31	1456
1993-06-30	1535
1993-12-31	1357
1994-06-30	673
1994-12-31	515
1995-06-30	816
1995-12-31	938
1996-06-30	861
1996-12-31	659
1997-06-30	719
1997-12-31	1079
1998-06-30	1736
1998-12-31	2884
1999-06-30	1441