user: Question: What is the average overall rank of all players drafted from duke after round 9?
Columns: ['Round', 'Overall', 'Player', 'Position', 'School/Club Team']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 20.0, 'Willis Adams', 'Wide Receiver', 'Houston']
SQL:

assistant: SELECT AVG("Overall") FROM "Table" WHERE "School/Club Team" = 'duke' AND "Round" > 9.0;