user: Question: What is the average win percentage of a season with a GB of 5?
Columns: ['Year', 'Record [a ]', 'Win %', 'League [b ]', 'Division [c ]', 'GB [d ]', 'Post-season record [e ]', 'Post-season win %', 'MLB affiliate [f ]']
Types: ['text', 'text', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1978', '64–77', 0.454, '9th', '4th', '22½', '—', '—', 'Cincinnati Reds']
SQL:

assistant: SELECT AVG("Win %") FROM "Table" WHERE "GB [d ]" = '5';