user: Question: What is the average round of the match with Kevin Manderson as the opponent?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Time', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Loss', '11–5', 'Rafael dos Anjos', 'Decision (unanimous)', 'UFC 154', 3.0, '5:00', 'Montreal, Quebec , Canada']
SQL:

assistant: SELECT AVG("Round") FROM "Table" WHERE "Opponent" = 'Kevin Manderson';