What is the 2012 Employees (Total) when the rank (2012) is 7?
CREATE TABLE "largest_employers" (
  "rank_2012" real,
  "rank_2010" real,
  "employer" text,
  "industry" text,
  "2012_employees_total" real,
  "2010_employees_total" real,
  "2007_employees_total" text,
  "head_office" text
);
SELECT "2012_employees_total" FROM "largest_employers" WHERE "rank_2012"=7;