Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_91 (lost INTEGER, win__percentage VARCHAR, opponent VARCHAR)
### Question:
What is the largest number Lost to david nalbandian with a Win Rate of 20%?
### Answer:
SELECT MAX(lost) FROM table_name_91 WHERE win__percentage = "20%" AND opponent = "david nalbandian"