Name the number of class aaaaa for 1988-89
CREATE TABLE "team" (
  "school_year" text,
  "class_a" text,
  "class_aa" text,
  "class_aaa" text,
  "class_aaaa" text,
  "class_aaaaa" text
);
SELECT COUNT("class_aaaaa") FROM "team" WHERE "school_year"='1988-89';