What is the largest number Lost to david nalbandian with a Win Rate of 20%?
CREATE TABLE table_name_91 (
    lost INTEGER,
    win__percentage VARCHAR,
    opponent VARCHAR
)
SELECT MAX(lost) FROM table_name_91 WHERE win__percentage = "20%" AND opponent = "david nalbandian"
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 largest number Lost to david nalbandian with a Win Rate of 20%? ### Input: CREATE TABLE table_name_91 (
    lost INTEGER,
    win__percentage VARCHAR,
    opponent VARCHAR
) ### Response: SELECT MAX(lost) FROM table_name_91 WHERE win__percentage = "20%" AND opponent = "david nalbandian"