What team did carlos cardus drive for in 1983 when he got less than 21 points?
CREATE TABLE "motorcycle_grand_prix_results" (
  "year" real,
  "class" text,
  "team" text,
  "points" real,
  "rank" text,
  "wins" real
);
SELECT "team" FROM "motorcycle_grand_prix_results" WHERE "points"<21 AND "year"=1983;