CREATE TABLE table_name_40 (average_population__x_1000_ INTEGER, deaths VARCHAR, crude_death_rate__per_1000_ VARCHAR)
What is the average population when deaths are 3 557 and crude death date is less than 11.9?
SELECT AVG(average_population__x_1000_) FROM table_name_40 WHERE deaths = "3 557" AND crude_death_rate__per_1000_ < 11.9