What's the average men's wheelchair when women's wheelchair is less than 0?
CREATE TABLE "victories_by_nationality" (
  "country" text,
  "men_s_race" real,
  "women_s_race" real,
  "men_s_wheelchair" real,
  "women_s_wheelchair" real,
  "total" real
);
SELECT AVG("men_s_wheelchair") FROM "victories_by_nationality" WHERE "women_s_wheelchair"<0;