What average deaths have 15,0 as the IMR, with a CDR greater than 4,0?
CREATE TABLE "births_and_deaths" (
  "periodo" text,
  "births" real,
  "deaths" real,
  "difference" real,
  "cbr" real,
  "cdr" real,
  "imr" real,
  "tfr" real
);
SELECT AVG("deaths") FROM "births_and_deaths" WHERE "imr"='15,0' AND "cdr">'4,0';