What is the highest score in round 4 and total of 284 in a year more recent than 1998?
CREATE TABLE "tournaments" (
  "year" real,
  "tournament" text,
  "round_1" real,
  "round_2" real,
  "round_3" real,
  "round_4" real,
  "score" real,
  "to_par" text,
  "place" text,
  "money" real
);
SELECT MAX("round_4") FROM "tournaments" WHERE "score"=284 AND "year">1998;