CREATE TABLE table_name_18 (loses INTEGER, wins VARCHAR(255), draws VARCHAR(255), year VARCHAR(255), competition VARCHAR(255))
What sum of Losses has Year greater than 1972, and Competition of nswrfl, and Draws 0, and Wins 16?
    
SQL: SELECT SUM(loses) FROM table_name_18 WHERE year > 1972 AND competition = "nswrfl" AND draws = 0 AND wins = 16