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_13836704_9 (freight__metric_tonnes_ INTEGER, airport VARCHAR)
### Question:
what is the maximum freight (metric tonnes) with airport being liverpool
### Answer:
SELECT MAX(freight__metric_tonnes_) FROM table_13836704_9 WHERE airport = "Liverpool"