user: Question: what number is us viewers in season 12?
Columns: ['No. in series', 'No. in 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: [27.0, 1.0, '"Charlie is 2!"', 'Bob Koherr', 'Erika Kaestle & Patrick McCarthy', 'February20,2011', 202.0, '4.2']
SQL:

assistant: SELECT "U.S. viewers (millions)" FROM "Table" WHERE "No. in season" = 12.0;