CREATE TABLE "membership" (
  "school" text,
  "location" text,
  "mascot" text,
  "county" text,
  "year_joined" real,
  "previous_conference" text,
  "year_left" real,
  "conference_joined" text
);

Question: Of all the schools that left before 2003, what is the average year joined?
SQL: SELECT AVG("year_joined") FROM "membership" WHERE "year_left"<2003;

Question: What year did the Ingots, who left after 2007, join?
SQL: SELECT COUNT("year_joined") FROM "membership" WHERE "mascot"='ingots' AND "year_left">2007;