Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
How many items were under ranking l.a.(2) when the world ranking was 21st?

### Inputs:
table_name: table, columns: ['Index (Year)', 'Author / Editor / Source', 'Year of publication', 'Countries sampled', 'World Ranking (1)', 'Ranking L.A. (2)']

### Response:
SELECT COUNT Ranking L.A. (2) FROM table WHERE World Ranking (1) = 21st