How many states were there when there was an enrollment of 2789?
CREATE TABLE "member_schools" (
  "institution" text,
  "city" text,
  "state" text,
  "team_name" text,
  "affiliation" text,
  "enrollment" real,
  "home_conference" text
);
SELECT COUNT("state") FROM "member_schools" WHERE "enrollment"=2789;