Which Big (>500ha) has a Micro (10ha) larger than 940, and a Department of potosí, and a Total smaller than 16,240?
CREATE TABLE "irrigation_infrastructure" (
  "department" text,
  "micro_10ha" real,
  "small_100ha" real,
  "medium_500ha" real,
  "big_500ha" real,
  "total" real
);
SELECT MAX("big_500ha") FROM "irrigation_infrastructure" WHERE "micro_10ha">940 AND "department"='potosí' AND "total"<'16,240';