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_99 (gold INTEGER, bronze VARCHAR, silver VARCHAR, total VARCHAR)
### Question:
What is the average number of gold medals won among participants that won less than 13 silver, less than 8 bronze, and more than 18 medals overall?
### Answer:
SELECT AVG(gold) FROM table_name_99 WHERE silver < 13 AND total > 18 AND bronze < 8