What is the average round when there is a defensive back and an overall smaller than 199?
CREATE TABLE table_32177 (
    "Round" real,
    "Overall" real,
    "Player" text,
    "Position" text,
    "School/Club Team" text
)
SELECT AVG("Round") FROM table_32177 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_32177 (
    "Round" real,
    "Overall" real,
    "Player" text,
    "Position" text,
    "School/Club Team" text
) ### Response: SELECT AVG("Round") FROM table_32177 WHERE "Position" = 'defensive back' AND "Overall" < '199'