Table schema:
CREATE TABLE table_name_89 (gold INTEGER, total VARCHAR, nation VARCHAR, bronze VARCHAR, silver VARCHAR)

Question: What's the sum of Gold with a Bronze that's larger than 15, Silver that's smaller than 197, the Nation of Saint Lucia, and has a Total that is larger than 50?
SQL: SELECT SUM(gold) FROM table_name_89 WHERE bronze > 15 AND silver < 197 AND nation = "saint lucia" AND total > 50