Bi-annual	US dollars
1987-06-30	1369
1987-12-31	1851
1988-06-30	1774
1988-12-31	1692
1989-06-30	1856
1989-12-31	1922
1990-06-30	2475
1990-12-31	3440
1991-06-30	2977
1991-12-31	3002
1992-06-30	3186
1992-12-31	3601
1993-06-30	4988
1993-12-31	4997
1994-06-30	4610
1994-12-31	6802
1995-06-30	8399
1995-12-31	6669
1996-06-30	7669
1996-12-31	6189
1997-06-30	7222
1997-12-31	6588
1998-06-30	7374
1998-12-31	8350
1999-06-30	8545