Bi-annual	US dollars
1987-06-30	1793
1987-12-31	1676
1988-06-30	1987
1988-12-31	1902
1989-06-30	1914
1989-12-31	1587
1990-06-30	1334
1990-12-31	1781
1991-06-30	1876
1991-12-31	2703
1992-06-30	3001
1992-12-31	4183
1993-06-30	11218
1993-12-31	11765
1994-06-30	9148
1994-12-31	20687
1995-06-30	20896
1995-12-31	24542
1996-06-30	25180
1996-12-31	29348
1997-06-30	28041
1997-12-31	30950
1998-06-30	42885
1998-12-31	37520
1999-06-30	36796