How many years are there where the the under-15 is Arturo Salazar Martinez and the under-19 is Moises Galvez?
CREATE TABLE "boys" (
  "year" real,
  "under_11" text,
  "under_13" text,
  "under_15" text,
  "under_17" text,
  "under_19" text
);
SELECT COUNT("year") FROM "boys" WHERE "under_15"='Arturo Salazar Martinez' AND "under_19"='Moises Galvez';