Which Size has an IHSAA Class of aa, and a Location of milan?
CREATE TABLE "indiana_high_school_athletics_conference" (
  "school" text,
  "location" text,
  "mascot" text,
  "size" real,
  "ihsaa_class" text,
  "county" text
);
SELECT SUM("size") FROM "indiana_high_school_athletics_conference" WHERE "ihsaa_class"='aa' AND "location"='milan';