What were the fewest number of Sri Lankans admitted when more than 4,270 Bangladeshis and more than 4,986 Pakistanis were admitted?
CREATE TABLE "immigration" (
  "year" text,
  "indians_admitted" real,
  "pakistanis_admitted" real,
  "sri_lankans_admitted" real,
  "bangladeshis_admitted" real,
  "nepalis_admitted" real
);
SELECT MIN("sri_lankans_admitted") FROM "immigration" WHERE "bangladeshis_admitted">'4,270' AND "pakistanis_admitted">'4,986';