What's the shut down state of the unit that's been in commercial operation since 01.02.1984?
CREATE TABLE "reactors" (
  "unit" text,
  "type" text,
  "net_power" text,
  "total_power" text,
  "construction_start" text,
  "construction_finish" text,
  "commercial_operation" text,
  "shut_down" text
);
SELECT "shut_down" FROM "reactors" WHERE "commercial_operation"='01.02.1984';