CREATE TABLE table_204_678 (id NUMBER, "record" CLOB, "athlete" CLOB, "nation" CLOB, "venue" CLOB, "date" CLOB, "#" NUMBER)

which nation has set the record the most times ?
SELECT "nation" FROM table_204_678 GROUP BY "nation" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "nation" FROM "table_204_678" GROUP BY "nation" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY