CREATE TABLE table_name_27 (events INTEGER, top_5 VARCHAR(255), top_10 VARCHAR(255), tournament VARCHAR(255))
What is the average number of events of PGA Championship tournaments with a top-5 less than 0?
    
SQL: SELECT AVG(events) FROM table_name_27 WHERE top_10 = 0 AND tournament = "pga championship" AND top_5 < 0