user: Question: What is the round number when the record is 15–7–1?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Time', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Win', '17–11–1', 'Nick Gonzalez', 'Submission (rear naked choke)', 'Legacy FC 23', 3.0, '4:43', 'San Antonio, Texas , United States']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Record" = '15–7–1';