Name the total number of class aaa for 2006-07
CREATE TABLE "individual" (
  "school_year" text,
  "class_a" text,
  "class_aa" text,
  "class_aaa" text,
  "class_aaaa" text,
  "class_aaaaa" text
);
SELECT COUNT("class_aaa") FROM "individual" WHERE "school_year"='2006-07';