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

### Instruction:
What is the average Density of 53 No. munic.?

### Inputs:
table_name: table, columns: ['Abbr', 'Canton', 'Capital', 'Density (per km²)', 'No. munic.', 's Official language']

### Response:
SELECT AVG Density (per km²) FROM table WHERE No. munic. = 53