user: Question: How many series had 18.77 million viewers?
Columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production Code', 'U.S. viewers (millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: [48.0, 1.0, '"In The Dark"', 'Paul Holohan', 'Hank Steinberg', 'September23,2004', 175301.0, '21.51']
SQL:

assistant: SELECT COUNT("Series #") FROM "Table" WHERE "U.S. viewers (millions)" = '18.77';