user: Question: What round did the fight last when Mikhail Ilyukhin's record was 15-5?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Round', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Win', '30-11-1', 'Jordanas Poskaitis', 'Submission (leglock)', 'N/A', 'Vilnius , Lithuania']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Record" = '15-5';