Bi-annual	US dollars
1987-06-30	2391
1987-12-31	2430
1988-06-30	2243
1988-12-31	2370
1989-06-30	2032
1989-12-31	2053
1990-06-30	1828
1990-12-31	1966
1991-06-30	1824
1991-12-31	2172
1992-06-30	2008
1992-12-31	1865
1993-06-30	3024
1993-12-31	3487
1994-06-30	4370
1994-12-31	4639
1995-06-30	4720
1995-12-31	5923
1996-06-30	5873
1996-12-31	7233
1997-06-30	7643
1997-12-31	7440
1998-06-30	7454
1998-12-31	7130
1999-06-30	6489