Bi-annual	US dollars
1987-06-30	2519
1987-12-31	2708
1988-06-30	2688
1988-12-31	2423
1989-06-30	1848
1989-12-31	1972
1990-06-30	2213
1990-12-31	2647
1991-06-30	1980
1991-12-31	2918
1992-06-30	2552
1992-12-31	4827
1993-06-30	11273
1993-12-31	12205
1994-06-30	7224
1994-12-31	15123
1995-06-30	15594
1995-12-31	15668
1996-06-30	16410
1996-12-31	15443
1997-06-30	18757
1997-12-31	20089
1998-06-30	29361
1998-12-31	21575
1999-06-30	19292