Which 2nd leg came after a 1st leg of 0-3?
CREATE TABLE "round_16" (
  "team_1" text,
  "agg" text,
  "team_2" text,
  "1st_leg" text,
  "2nd_leg" text
);
SELECT "2nd_leg" FROM "round_16" WHERE "1st_leg"='0-3';