What's the Air Force - Navy score in the 2018 season?
CREATE TABLE "table1_1850339_2" (
  "season" real,
  "trophy_winner" text,
  "air_force_navy_score" text,
  "air_force_army_score" text,
  "army_navy_score" text
);
SELECT "air_force_navy_score" FROM "table1_1850339_2" WHERE "season"=2018;