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_81 (attendance INTEGER, opponent VARCHAR, record VARCHAR)
### Question:
What was the average attendance when the New York Mets were opponents with a record of 51-33?
### Answer:
SELECT AVG(attendance) FROM table_name_81 WHERE opponent = "new york mets" AND record = "51-33"