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_31 (silver INTEGER, rank VARCHAR, bronze VARCHAR)
### Question:
What is the average number of silvers for teams ranked 5 with 0 bronze?
### Answer:
SELECT AVG(silver) FROM table_name_31 WHERE rank = "5" AND bronze < 0