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

### Instruction:
How many ranks have a rebound average smaller than 6.1?

### Inputs:
table_name: table, columns: ['Rank', 'Player', 'Years', 'Games', 'Reb. Avg.', 'Total Rebounds']

### Response:
SELECT COUNT Rank FROM table WHERE Reb. Avg. < 6.1