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

### Instruction:
WHAT IS THE LOWEST ELECTORATE WITH 31,511 VOTES, AND PERCENT YES SMALLER THAN 57.2?

### Inputs:
table_name: table, columns: ['Constituency', 'Electorate', 'Votes', 'Turnout', 'Spoilt', 'Percent Yes']

### Response:
SELECT MIN Electorate FROM table WHERE Votes = 31,511 AND Percent Yes < 57.2