What is the average round when there is a defensive back and an overall smaller than 199?
CREATE TABLE table_name_49 (
    round INTEGER,
    position VARCHAR,
    overall VARCHAR
)
SELECT AVG(round) FROM table_name_49 WHERE position = "defensive back" AND overall < 199
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 is the average round when there is a defensive back and an overall smaller than 199? ### Input: CREATE TABLE table_name_49 (
    round INTEGER,
    position VARCHAR,
    overall VARCHAR
) ### Response: SELECT AVG(round) FROM table_name_49 WHERE position = "defensive back" AND overall < 199