Bi-annual	US dollars
1987-06-30	1005
1987-12-31	1117
1988-06-30	1045
1988-12-31	1043
1989-06-30	910
1989-12-31	519
1990-06-30	732
1990-12-31	1050
1991-06-30	1056
1991-12-31	1053
1992-06-30	2381
1992-12-31	2207
1993-06-30	3207
1993-12-31	3974
1994-06-30	4015
1994-12-31	4315
1995-06-30	4900
1995-12-31	4089
1996-06-30	4919
1996-12-31	5169
1997-06-30	4977
1997-12-31	4105
1998-06-30	7478
1998-12-31	5676
1999-06-30	7181