CREATE TABLE table_name_74 (time_retired VARCHAR(255), grid VARCHAR(255), laps VARCHAR(255), manufacturer VARCHAR(255))
What is the time/retired for the rider with the manufacturuer yamaha, grod of 1 and 21 total laps?
    
SQL: SELECT time_retired FROM table_name_74 WHERE laps = "21" AND manufacturer = "yamaha" AND grid = "1"