Tell me the total number of years for wins less than 2 and class of 50cc with points of 15
CREATE TABLE "motorcycle_grand_prix_results" (
  "year" real,
  "class" text,
  "team" text,
  "points" real,
  "rank" text,
  "wins" real
);
SELECT COUNT("year") FROM "motorcycle_grand_prix_results" WHERE "wins"<2 AND "class"='50cc' AND "points"=15;