user: Question: How many u.s. viewers  (million) have the production code of 5.09?
Columns: ['No.', '#', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [89.0, 1.0, '"Revival"', 'Steward Lee', 'Chris Collins', 'September29,2012', '4.26', '1.94']
SQL:

assistant: SELECT "U.S. viewers (million)" FROM "Table" WHERE "Production code" = '5.09';