Bi-annual	US dollars
1987-06-30	1622
1987-12-31	2000
1988-06-30	1639
1988-12-31	1819
1989-06-30	1918
1989-12-31	2112
1990-06-30	1777
1990-12-31	1654
1991-06-30	1667
1991-12-31	1784
1992-06-30	2002
1992-12-31	3122
1993-06-30	3724
1993-12-31	5408
1994-06-30	4526
1994-12-31	5690
1995-06-30	4195
1995-12-31	3349
1996-06-30	5053
1996-12-31	5064
1997-06-30	3607
1997-12-31	4123
1998-06-30	4638
1998-12-31	4415
1999-06-30	3321