Bi-annual	US dollars
1987-06-30	2962
1987-12-31	3821
1988-06-30	3609
1988-12-31	3437
1989-06-30	3677
1989-12-31	3443
1990-06-30	3758
1990-12-31	3730
1991-06-30	3309
1991-12-31	3145
1992-06-30	3058
1992-12-31	2768
1993-06-30	2615
1993-12-31	2384
1994-06-30	2117
1994-12-31	1838
1995-06-30	1257
1995-12-31	1138
1996-06-30	1047
1996-12-31	883
1997-06-30	759
1997-12-31	711
1998-06-30	824
1998-12-31	691
1999-06-30	645