user: Question: How many entries are there for u.s. viewers (millions) for the episode directed by Rob Bailey?
Columns: ['No.', '#', 'Title', 'Directed by', 'Story by', 'Teleplay by', 'Original air date', 'U.S. viewers (millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [11.0, 1.0, '"Accentuate the Positive"', 'Anthony Hemingway', 'Eric Overmyer & Anthony Bourdain', 'Eric Overmyer', 'April24,2011', '0.61']
SQL:

assistant: SELECT COUNT("U.S. viewers (millions)") FROM "Table" WHERE "Directed by" = 'Rob Bailey';