user: Question: What was the date of the game with a decision of Lehtonen and attended by more than 17731 people?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Decision', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['December 1', 'Atlanta', '4 – 0', 'NY Islanders', 'Lehtonen', 15355.0, '12–13–0']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Decision" = 'Lehtonen' AND "Attendance" > 17731.0;