between car plates of 80-84 what is the population in 1000 in year 1931?
CREATE TABLE "polish_voivodeships_1919_1939" (
  "car_plates_since_1937" text,
  "voivodeship_separate_city" text,
  "capital" text,
  "area_in_1000km_1930" text,
  "population_in_1000_1931" text
);
SELECT "population_in_1000_1931" FROM "polish_voivodeships_1919_1939" WHERE "car_plates_since_1937"='80-84';