Name the 1821 with 1811 of 1921
CREATE TABLE "demography" (
  "year" text,
  "1801" text,
  "1811" text,
  "1821" text,
  "1841" text,
  "1851" text,
  "1861" text,
  "1871" text,
  "1881" text,
  "1891" text,
  "1901" text
);
SELECT "1821" FROM "demography" WHERE "1811"='1921';