How many schools are located in South Brisbane?
CREATE TABLE "winning_head_of_the_river_championship_e" (
  "school" text,
  "location" text,
  "enrolment" real,
  "founded" real,
  "denomination" text,
  "day_boarding" text,
  "school_colours" text,
  "abbreviation" text,
  "in_competition_since" real
);
SELECT COUNT("school") FROM "winning_head_of_the_river_championship_e" WHERE "location"='South Brisbane';