Bi-annual	US dollars
1987-06-30	685
1987-12-31	1042
1988-06-30	1035
1988-12-31	1041
1989-06-30	1268
1989-12-31	1269
1990-06-30	1683
1990-12-31	2537
1991-06-30	2093
1991-12-31	2253
1992-06-30	2377
1992-12-31	2430
1993-06-30	3334
1993-12-31	3515
1994-06-30	3128
1994-12-31	3808
1995-06-30	4434
1995-12-31	2485
1996-06-30	2947
1996-12-31	2871
1997-06-30	4997
1997-12-31	3422
1998-06-30	3826
1998-12-31	4726
1999-06-30	3674