OK, just to make sure if have this right, it goes like this?
Block Condition_file
1 1 (15 rows)
1 2 (15 rows)
1 3 (15 rows)
2 1 (another 15 rows)
2 2 (another 15 rows)
2 3 (another 15 rows)
3 1 (remaining 15 rows)
3 2 (remaining 15 rows)
3 3 (remaining 15 rows)