How many writers are listed when the U.S viewers are 11.21 million?
CREATE TABLE table_24910733_1 (
    written_by VARCHAR,
    us_viewers__millions_ VARCHAR
)
SELECT COUNT(written_by) FROM table_24910733_1 WHERE us_viewers__millions_ = "11.21"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many writers are listed when the U.S viewers are 11.21 million? ### Input: CREATE TABLE table_24910733_1 (
    written_by VARCHAR,
    us_viewers__millions_ VARCHAR
) ### Response: SELECT COUNT(written_by) FROM table_24910733_1 WHERE us_viewers__millions_ = "11.21"