CREATE TABLE table_name_89 (gold INTEGER, total VARCHAR(255), nation VARCHAR(255), bronze VARCHAR(255), silver VARCHAR(255))
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