What source has a cardwell of 20%?
CREATE TABLE table_name_18 (
    source VARCHAR,
    cardwell VARCHAR
)
SELECT source FROM table_name_18 WHERE cardwell = "20%"
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: What source has a cardwell of 20%? ### Input: CREATE TABLE table_name_18 (
    source VARCHAR,
    cardwell VARCHAR
) ### Response: SELECT source FROM table_name_18 WHERE cardwell = "20%"