In what season was the final placing NC† and the team SL Formula Racing? 
CREATE TABLE "career_summary" (
  "season" real,
  "series" text,
  "team_name" text,
  "races" real,
  "wins" real,
  "points" text,
  "final_placing" text
);
SELECT "season" FROM "career_summary" WHERE "final_placing"='NC†' AND "team_name"='SL Formula Racing';