user: Question: how many guest stars did the episode that was broadcasted 11September2012 have
Columns: ['Episode', 'Broadcast date', 'Guest(s)', 'Singer(s)', 'Ratings']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, '14August2012', 'Michael McIntyre and Alex James', 'Amy Macdonald', '1.44m']
SQL:

assistant: SELECT "Guest(s)" FROM "Table" WHERE "Broadcast date" = '11September2012';