Name the most male life expectancy for pakistan
CREATE TABLE "list_by_the_world_health_organization_20" (
  "overall_rank" real,
  "country" text,
  "overall_life_expectancy" real,
  "male_life_expectancy" real,
  "male_rank" real,
  "female_life_expectancy" real,
  "female_rank" real
);
SELECT MAX("male_life_expectancy") FROM "list_by_the_world_health_organization_20" WHERE "country"='Pakistan';