In which host city was Margaret Thatcher the President-in-Office in 1981?
CREATE TABLE "1975_2009" (
  "year" real,
  "date" text,
  "type" text,
  "eu_council_presidency" text,
  "president_in_office" text,
  "host_city" text
);
SELECT "host_city" FROM "1975_2009" WHERE "president_in_office"='margaret thatcher' AND "year"=1981;