How many episodes were watched by 12.72 million U.S. viewers?
CREATE TABLE table_12570759_2 (
    written_by VARCHAR,
    us_viewers__millions_ VARCHAR
)
SELECT COUNT(written_by) FROM table_12570759_2 WHERE us_viewers__millions_ = "12.72"
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 episodes were watched by 12.72 million U.S. viewers? ### Input: CREATE TABLE table_12570759_2 (
    written_by VARCHAR,
    us_viewers__millions_ VARCHAR
) ### Response: SELECT COUNT(written_by) FROM table_12570759_2 WHERE us_viewers__millions_ = "12.72"