What is the coinage metal for a KM number of S75?
CREATE TABLE "later_thalers_with_event_location_and_ye" (
  "location" text,
  "date" real,
  "denomination" text,
  "coinage_metal" text,
  "mintage" real,
  "km_number" text
);
SELECT "coinage_metal" FROM "later_thalers_with_event_location_and_ye" WHERE "km_number"='S75';