Bi-annual	US dollars
1987-06-30	1775
1987-12-31	2164
1988-06-30	2081
1988-12-31	1810
1989-06-30	1685
1989-12-31	1443
1990-06-30	1880
1990-12-31	1721
1991-06-30	1649
1991-12-31	1789
1992-06-30	2095
1992-12-31	1968
1993-06-30	2939
1993-12-31	2653
1994-06-30	3267
1994-12-31	3675
1995-06-30	3699
1995-12-31	3706
1996-06-30	4694
1996-12-31	4652
1997-06-30	6944
1997-12-31	9028
1998-06-30	8748
1998-12-31	9443
1999-06-30	10487