How much tonnage has a Fate of sunk, and a Flag of great britain, and a Date of 26 september 1940, and Deaths of 2?
CREATE TABLE "summary_of_raiding_history" (
  "date" text,
  "ship_name" text,
  "flag" text,
  "tonnage_grt" real,
  "fate" text,
  "deaths" real
);
SELECT SUM("tonnage_grt") FROM "summary_of_raiding_history" WHERE "fate"='sunk' AND "flag"='great britain' AND "date"='26 september 1940' AND "deaths"=2;