user: Question: What was the lowest lost entry for a team with fewer than 21 goals for?
Columns: ['Position', 'Team', 'Played', 'Drawn', 'Lost', 'Goals For', 'Goals Against', 'Goal Difference', 'Points 1']
Types: ['real', 'text', 'real', 'real', 'real', 'real', 'real', 'text', 'text']
Sample row: [1.0, 'Atherton Collieries', 24.0, 4.0, 4.0, 46.0, 22.0, '+24', '36']
SQL:

assistant: SELECT MIN("Lost") FROM "Table" WHERE "Goals For" < 21.0;