Bi-annual	US dollars
1987-06-30	2233
1987-12-31	2396
1988-06-30	2451
1988-12-31	2797
1989-06-30	2676
1989-12-31	3062
1990-06-30	2857
1990-12-31	3340
1991-06-30	2971
1991-12-31	3138
1992-06-30	3323
1992-12-31	2966
1993-06-30	3607
1993-12-31	5664
1994-06-30	6113
1994-12-31	6361
1995-06-30	6906
1995-12-31	7571
1996-06-30	7814
1996-12-31	8074
1997-06-30	8281
1997-12-31	10841
1998-06-30	11966
1998-12-31	11215
1999-06-30	10907