user: Question: What was the highest round that had Northwestern?
Columns: ['Round', 'Pick', 'Player', 'Position', 'School']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 3.0, 'Bruce Pickens', 'Defensive Back', 'Nebraska']
SQL:

assistant: SELECT MAX("Round") FROM "Table" WHERE "School" = 'Northwestern';