How many people lived in the voivodenship whose capital is Siedlce in the year of 1980?
CREATE TABLE "polish_voivodeships_and_separate_cities_" (
  "abbreviation" text,
  "voivodeship" text,
  "capital" text,
  "area_km_1998" text,
  "population_1980" text,
  "no_of_cities" real,
  "no_of_communes" real
);
SELECT "population_1980" FROM "polish_voivodeships_and_separate_cities_" WHERE "capital"='Siedlce';