what is the rank when the mountain peak is isthmus peak?
CREATE TABLE "the_200_most_topographically_prominent_m" (
  "rank" real,
  "mountain_peak" text,
  "region" text,
  "mountain_range" text,
  "location" text
);
SELECT "rank" FROM "the_200_most_topographically_prominent_m" WHERE "mountain_peak"='isthmus peak';