Bi-annual	US dollars
1987-06-30	2512
1987-12-31	3121
1988-06-30	4010
1988-12-31	4117
1989-06-30	3986
1989-12-31	3577
1990-06-30	3235
1990-12-31	3218
1991-06-30	2836
1991-12-31	3866
1992-06-30	5395
1992-12-31	4963
1993-06-30	7024
1993-12-31	7454
1994-06-30	7701
1994-12-31	8885
1995-06-30	8762
1995-12-31	8166
1996-06-30	8920
1996-12-31	9837
1997-06-30	9847
1997-12-31	9666
1998-06-30	13797
1998-12-31	15152
1999-06-30	15386