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
);

Question: what is the capital with the Voivodeship Separate city of białostockie?
SQL: SELECT "capital" FROM "polish_voivodeships_1919_1939" WHERE "voivodeship_separate_city"='białostockie';

Question: between car plates of 80-84 what is the population in 1000 in year 1931?
SQL: SELECT "population_in_1000_1931" FROM "polish_voivodeships_1919_1939" WHERE "car_plates_since_1937"='80-84';

Question: tell me the population in 1000(1931) that has car plates since 1937 of 35-39.
SQL: SELECT "population_in_1000_1931" FROM "polish_voivodeships_1919_1939" WHERE "car_plates_since_1937"='35-39';

Question: tell me the name of the capital with an area of 20,4.
SQL: SELECT "capital" FROM "polish_voivodeships_1919_1939" WHERE "area_in_1000km_1930"='20,4';