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_28 (gold INTEGER, nation VARCHAR, silver VARCHAR)
### Question:
What is the average Gold, when Nation is Yugoslavia, and when Silver is greater than 0?
### Answer:
SELECT AVG(gold) FROM table_name_28 WHERE nation = "yugoslavia" AND silver > 0