How many Small catagories are there for the department that has a medium of 17101? 
CREATE TABLE "irrigation_infrastructure" (
  "department" text,
  "micro_10ha" real,
  "small_100ha" real,
  "medium_500ha" real,
  "big_500ha" real,
  "total" real
);
SELECT COUNT("small_100ha") FROM "irrigation_infrastructure" WHERE "medium_500ha"=17101;