CREATE TABLE table_203_340 (id DECIMAL, "rank" DECIMAL, "airport" TEXT, "passengers handled" DECIMAL, "% change 2011 / 12" DECIMAL)

which airport has the least amount of passengers going through london southend airport ?
SELECT "airport" FROM table_203_340 ORDER BY "passengers handled" LIMIT 1
SELECT "airport" FROM "table_203_340" ORDER BY "passengers handled" NULLS FIRST LIMIT 1