user: Question: What is the Nielsen ranking for Season 8?
Columns: ['Season', 'Episodes', 'First airdate', 'Last airdate', 'Nielsen ranking']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Season 1', 6.0, 'March 25, 1986', 'April 29, 1986', '#13']
SQL:

assistant: SELECT "Nielsen ranking" FROM "Table" WHERE "Season" = 'Season 8';