CREATE TABLE table_name_14 (population_in_1000__1931_ VARCHAR, car_plates__since_1937_ VARCHAR)

between car plates of 80-84 what is the population in 1000 in year 1931?
SELECT population_in_1000__1931_ FROM table_name_14 WHERE car_plates__since_1937_ = "80-84"
SELECT "population_in_1000__1931_" FROM "table_name_14" WHERE "80-84" = "car_plates__since_1937_"