When was the school in Salem, Massachusetts located?
CREATE TABLE "associate_members" (
  "institution" text,
  "location" text,
  "nickname" text,
  "founded" real,
  "type" text,
  "enrollment" real,
  "primary_conference" text,
  "lec_sport" text
);
SELECT "founded" FROM "associate_members" WHERE "location"='Salem, Massachusetts';