Which supercharger gear ratio has a Octane rating of 68?
CREATE TABLE "specifications_for_different_r_985_wasp_" (
  "engine" text,
  "power_continuous" text,
  "power_takeoff" text,
  "compression_ratio" text,
  "supercharger_gear_ratio" text,
  "octane_rating" text,
  "dry_weight" text
);
SELECT "supercharger_gear_ratio" FROM "specifications_for_different_r_985_wasp_" WHERE "octane_rating"='68';