What is the total enrollment at the school that has the nickname of the Fightin' Blue Hens?
CREATE TABLE "membership" (
  "school" text,
  "location" text,
  "founded" real,
  "affiliation" text,
  "enrollment" real,
  "nickname" text,
  "primary_conference" text
);
SELECT COUNT("enrollment") FROM "membership" WHERE "nickname"='fightin'' blue hens';